Mr. and Mrs. Thompson described the children's behaviour in their home from the time the children arrived until the time of trial. As they described it, the behaviour of each of the children, including their sexual behaviour, was quite extraordinary. Michael, though only ten, was openly given to cross-dressing, for example, and he made blatant sexual advances to Mrs. Thompson and her daughters. Similarly, Michelle made suggestive approaches to Mr. Thompson and others. And Kathy, too, exhibited highly sexualized behaviours. Even the dogs came in for sexual attention by the children. And all three children manifested deep insecurities and emotional turmoil, especially Michael, who was prone to frequent temper tantrums, fits of rage, and sudden descents into infantile behaviour.
Mrs. Thompson thought the boy seemed filled with fear and loathing of Donald W.. He would imitate people from time to time, including a person he said was Donald W., and when imitating this person, Mrs. Thompson said, Michael would become particularly aggressive with the girls.
She recalled that not long after the arrival of the children they began reporting past incidents of sexual activity, doing so reluctantly and with emotional difficulty at first, but more freely as time passed. Upset and confused by what she was hearing, Mrs. Thompson began making notes, recording some of the children's reports, along with her own thoughts. She also began telling Ms. Bunko-Ruys about what she was hearing. In time, Mrs. Thompson took the children, accompanied by Ms. Bunko-Ruys, to talk to Sergeant Dueck, who interviewed them in the presence of Ms. Bunko-Ruys and had the interviews video- taped.
Mrs. Thompson said in effect that the interviews came as something of a relief to her: It was reassuring that the children were prepared to open up with others, despite the painful and sometimes bizarre nature of what they had been telling her, and that they then recounted what they had told her.
Mrs. Thompson's notes were referred to extensively during her cross-examination by counsel for Donald R., who was interested in knowing more about the behaviours of the children, about what they had told her of their past experiences, and about their emotional states. The notes, which recorded more than what had been testified to by the children, disclosed that Michael had told her about "screwing bats" and the like; had threatened to leave because there was no one in the Thompson home to screw; had implicated some of the Klassens in sexual activity; had threatened the girls over their disclosures; and so on.
After continuing reliance on these notes, counsel for Mr. R. began encountering opposition to his method and line of inquiry. This was especially so in relation to some of the things the children had told Mrs. Thompson, as recorded in her notes, things which had not been put to the children during their cross-examination. Madame Justice Batten finally suggested counsel confine himself to the emotional states of the children.
This spawned the following ground of appeal, taken by Donald R.:
The learned Trial Judge erred in law in not allowing Defence Counsel to cross-examine the...complainant's foster mother with respect to their previous disclosures and the circumstances surrounding those disclosures relevant to the charges.
In arguing this ground of appeal, counsel submitted that Justice Batten had prevented him from getting at information in Mrs. Thompson's notes pertaining to two or three other matters--bizarre allegations and threats by Michael, for example, when confronted with having had sexual contact with his sisters; and bizarre embellishments by Michelle of a story pertaining to the death of a baby. With respect I do not think this amounts to very much of anything, especially in the context of the whole of the evidence of the children, Mrs. Thompson, and others. Counsel was given wide latitude in the cross-examination, and he cross-examined Mrs. Thompson at length. To suggest these added bits of information would have made any difference, when viewed in the context of the whole of what was adduced, is unrealistic in my opinion. And so I would not give effect to this ground of appeal.
Dr. Eleanor McKenna
Dr. McKenna, a paediatrician at University Hospital, testified to her examination of Michelle in September of 1987. She said she had found a two centimetre shallow linear laceration along the left labia minora, consistent with a fingernail scratch, a straddle injury, or a light cut by an object with a smooth edge. She had also found a "creamy discharge," along with "several blood spots" on the girls panties, saying the discharge resembled that commonly associated with irritation of the perineum--which can be caused by many things including a finger or a penis--and that blood spots were highly unusual prior to puberty. Following the examination, she reported "there is no question in my mind, given the history of physical findings, that the child was subjected to non-accidental trauma of the genital area."
Dr. McKenna went on to say that Michelle had told her in the course of the examination--as noted in the file at the time--that "My deaf daddy spanked my bum, then he put his fingers in my bum. It hurt." This evidence was received on the understanding, referred to earlier, that its admissibility would be determined later.
Dr. John Yelland, who had been practising family medicine for about ten years when he examined the children on June 5, 1990 and again on May 31, 1991, was called by counsel for the Crown to give evidence about what he had found, as an examining physician, and what in his opinion lay beneath the findings, as an expert "in the nature and cause of physical injuries which may bear upon sexual abuse." Counsel for Donald R. objected to Dr. Yelland expressing opinions about the underlying causes of what he had found, suggesting the doctor be limited to his observations in light of his limited qualifications.
The admission of expert evidence depends on the application of the following criteria: (i) relevance; (ii) necessity in assisting the trier of fact; (iii) the absence of any exclusionary rule; and (iv) a properly qualified expert: R. v. Mohan,  2 S.C.R. 9.
In the circumstances, the admission of expert evidence from Dr. Yelland in relation to the subject-matter at issue depended upon the need for opinion evidence in that connection and the qualifications he possessed.
As for the first of these, the basic requirement of R. v. Abbey  2 S.C.R. 24, at p. 42, had to be satisfied.
It was there said:
With respect to matters called for special knowledge, an expert in the field may draw inferences and state his opinion. An expert's function is precisely this: to provide the judge and jury with a ready-made inference which the judge and jury, due to the technical nature of the facts, are unable to formulate. "An expert's opinion is admissible to furnish the Court with scientific information which is likely to be outside the experience and knowledge of a judge or jury. If on the proven facts a judge or jury can form their own conclusions without help, then the opinion of the expert is unnecessary" (Turner (1974), 60 Crim. App. R. 80, at o, 83, per Lawton L.J.) [emphasis added].
In commenting upon this in R. v. Mohan, Mr. Justice Sopinka noted at p. 23 that whether expert evidence is necessary or unnecessary in this sense is not to by judged by "too strict a standard" and is generally dependent on whether the subject-matter is such "that ordinary people are unlikely to form a correct judgment about it, if unassisted by persons with special knowledge."
As for the second--the qualifications of Dr. Yelland-- Crown counsel had to show that this witness had acquired special or peculiar knowledge through study or training or experience in the subject-matter at issue, though the threshold for qualification is comparatively low. As Madame Justice McLachlin observed in R. v. Marquard (cited earlier) at p. 243:
The only requirement for the admission of expert opinion is that the "expert witness possesses special knowledge and experience going beyond that of the trier of fact": R. v. Beland,  2 S.C.R. 398, at p. 415. Deficiencies in the expertise go to weight, not admissibility. As stated by Sopinka, Lederman and Bryant, The Law of Evidence in Canada, (1992), at pp. 536-537:
The admissibility of such [expert] evidence does not depend upon the means by which that skill was acquired. As long as the court is satisfied that the witness is sufficiently experienced in the subject-matter at issue, the court will not be concerned with whether his or her skill was derived from specific studies or by practical training, although that may affect the weight to be given to the evidence.
Dr. Yelland stated that, as a physician practising family medicine, he had taken a particular interest in the subject of sexual abuse of children. He had attended seminars, researched the literature, spoken on the subject, and so on. He had also testified on the subject in the courts from time to time, and the Department of Social Services was referring children to him for examination in cases of suspected abuse.
This satisfied Madame Justice Batten that Dr. Yelland was qualified to give opinion evidence "as to the nature and cause of physical injuries which may bear upon sexual abuse," and with that, he testified about his examinations of each of the children, expressing various opinions as he went along.
The first set of examinations, conducted on June 5, 1990, was undertaken at the behest of the Department, following Michael's allegations of sexual abuse in the Klassen foster home. These examinations were made within a few days of the arrival of the girls at the Thompsons, and since sexual assault was suspected, Dr. Yelland concentrated the examinations on the children's genital and rectal areas, looking for bruising and abnormalities in those areas.
As for Michelle, he said he had found marked redness and increased vascular marking in the area of the labia minora; scarring on the entrance to the vagina from a healed tear; an intact hymen; and normal rectal tone.
Turning to Kathy, he said he had found distinct redness and rawness of the genital area, extending to the rectum; only a remnant of a hymen; scarring and fissuring of the rectal area; and some infection. He thought Michelle's condition was compatible, and Kathy's highly compatible, with past sexual abuse, but could not say when it might have occurred.
His examination of Michael revealed a raw and inflamed rectal area and decreased rectal tone, but no evidence of recent sodomization. Decreased rectal tone, he added, tends to restore in time, probably in months.
The second set of examinations, conducted on May 31, 1991, followed what Dr. Yelland referred to as "much more extensive disclosure from the children" suggesting a history of both physical and sexual abuse. In the circumstances, and having in the meantime become more conversant with the subject of child abuse, he said he had conducted a more extensive set of examinations the second time, this time looking for signs--cuts, scars, and so on-- of physical as well as sexual abuse of the sort which had been drawn to his attention. Turning first to Michelle, he said he had found small scars on the labia minora, on the hymen, and on the rectum, consistent with penetration of some sort; a marked decrease in rectal tone; scarring behind the right ear, consistent with a cut from a sharp object; and scarring on her forehead, right elbow, knees, and abdomen, consistent with burns. As for Kathy he noted that her hymen was largely gone, that she had a marked decrease in rectal tone, and that she also had rectal scarring. All of this was consistent, in his opinion, with digital or other forms of penetration of the vagina and rectum. Kathy also had a scar on her chest and a scar on her inner right thigh, both consistent with burns in his view. In addition she had a seven centimetre, S-shaped scar on her back, which suggested to him that she had been deliberately cut with a knife or other sharp instrument.
As for Michael, he found the boy's rectal tone markedly decreased; his rectum scarred; his back, right hand, and left calf scarred from what appeared to have been second or third degree burns; and his right chest scarred, just below the nipple, suggestive of an old puncture wound.
In sum, and generally speaking, Dr. Yelland was of the opinion each of the children had been subjected to sexual and physical abuse in the past, any where from a few months to several years ago, judging from the scars. The apparent tears, puncture, cuts, and burns had all healed, making it impossible to know when, more precisely, the injuries had occurred.
Justice Batten's ruling, qualifying Dr. Yelland to give opinion evidence, prompted the following ground of appeal by Donald R.: That [she] erred in law in qualifying a general practitioner, Dr. John Yelland, as an expert witness to give evidence as to the nature and causes of physical injury that may bear upon sexual abuse.
According to the submission of counsel for Mr. R., Dr. Yelland was an experienced physician, possessed of knowledge beyond that of Justice Batten, but he was not qualified to express opinions in the narrow area concerning "the nature and causes of physical injury that may bear upon sexual abuse."
Though no such objection had been made on behalf of Mr. W. at trial, his counsel on appeal submitted that the qualifications, training, and experience of Dr. Yelland, while satisfactorily equipping him to treat injuries of the sort experienced by the children, were not satisfactory when it came to the "identification and cause of physical injuries and injuries arising out of sexual abuse."
It should perhaps be noted that the submissions were no more specific than this, and that both the ground of appeal and the submissions in support of it were confined to the decision of Justice Batten to formally qualify Dr. Yelland as she had.
Precisely what was encompassed by her having qualified him as an expert "as to the nature and cause of physical injuries which may bear upon sexual abuse," is difficult to say. It might have been better had he been qualified in more precise and perhaps somewhat larger terms in light of what was to come, for he was going to be called upon to express opinions in relation to both sets of examinations, the first confined to signs of sexual abuse, the second extending to signs of both sexual and physical abuse. But as a physician who had taken a particular interest in the subject of sexual abuse of children and who was experienced in the field he was certainly equipped to offer some legitimate opinion evidence as to the causal inferences which might be drawn from this finding or that. In light of that, and having regard for what was said of the law in R. v. Marquard, I do not think Justice Batten erred in qualifying him as she did. Whether she intended in doing so to qualify him to express some of the specific opinions he expressed--that this or that scar was indicative of a burn or a puncture wound, for example--is not clear. And whether he was adequately equipped for that is perhaps debatable. But he expressed his views, and since the submissions did not extend beyond taking issue with Justice Batten's decision to qualify him as she did, I do not intend to comment further, except to say that in the circumstances this would go to weight only.
Ms. Carol Bunko-Ruys.
Ms. Bunko-Ruys held a Bachelor of Arts from the University of Victoria, Faculty of Human and Social Development, and had worked with dysfunctional children for a number of years. Besides running group workshops and that sort of thing, she had been in private practice as a child therapist and consultant for about four years when the children were referred to her. She was being consulted from time to time by rural school boards experiencing difficulty with youngsters.
In light of her education and experience, the Crown sought to have her qualified as an expert witness, enabling her to go beyond her observations of the children and express certain opinions. Defence counsel objected, suggesting in particular that she was not qualified to express opinions about "whether or not certain characteristics are indicators of past abuse, and what form of abuse, and who that abuse may have been with." As for the last of these, it was said in effect that the investigation of sexual abuse, and the identification of abusers, was clearly beyond her expertise.
Ms. Bunko-Ruys stated that she had worked, as a therapist, with approximately a hundred abused children-- about half of whom had histories of sexual abuse--and had provided advice, as a consultant, on dealing with dysfunctional children. She had had no training or experience, however, in investigating sexual abuse or in identifying abusers. Indeed in her work as a therapist, she said, she did not consider it her role to question what children told her or to try to determine the truth of it.
It thus became clear that, while she might have been able to offer some opinion evidence of assistance to the Court, she was in no position to do so in relation to the investigation of allegations of sexual abuse or the identification of suspected abusers, assuming such evidence was otherwise admissible.
Having heard the matter out, Justice Batten ruled that Ms. Bunko-Ruys was qualified to give expert opinion evidence as to "the behavioral, social, and emotional characteristics of sexually abused children."
And so Ms. Bunko-Ruys, in addition to testifying about her own observations of the R. children, whom she described as "some of the most dysfunctional children I've ever worked with," was permitted to express a number of opinions. Some were of a general nature, relating for example to the developmental stages of children and to the indications and causes of arrested development at this or that stage. Some were more specific.
She expressed the specific opinion that the R. children, who showed signs of having been sexually abused, had been "traumatized at relatively early stages of their development," explaining that she could not say they had been subjected to some trauma during this month or that year, or even at age three necessarily, but that she could say, based upon her experience and the literature with which she was familiar, that the children had been traumatized early in their emotional development, as indicated by the lack of such early developmental traits as basic trust and a sense of safety and security which she had observed in the children. She was cross-examined about this, allowing that forms of trauma related to separation, most particularly removal from the birth home, could cause developmental difficulties of the sort experienced by the R. children.
She was also cross-examined, by counsel for Donald R., about the interviews of the children conducted by Sergeant Dueck. She had been present, in her capacity as the children's therapist and as "a supportive person," and she had apparently assisted them during the interviews, though none of this was made very clear. At any rate, counsel asked her about what the children had said in relation to this or that matter, and about whether children might eventually be induced to respond positively to a question if repeated often enough. She recalled what she could of the children's disclosures and expressed the view children could probably be induced to say "yes" to a question, though having first said "no," if the question were to be asked over and over again. Unable, however, to remember some of the things the children had said, and how many times this or that question might have been asked, she was invited from time to time to time to refresh her memory by reference to a document in the possession of counsel for the defence.
The document was being taken by counsel--as it had been earlier, during the cross-examination of the children- -as constituting a "transcript" or "transcripts" of Sergeant Dueck's interviews. It seems the defence, who had been given copies of the video-tapes, had had the tapes transcribed by someone, though the document had not been proved, as such, nor entered in evidence, either by agreement or otherwise. Indeed Sergeant Dueck, who had earlier been examined and cross-examined, had not been asked about the document. Nor had he been cross-examined along the line of how the interviews had been conducted.
Eventually counsel's tack in having Ms. Bunko-Ruys turn to the document to refresh her memory, especially in the context of the manner in which the children had been interviewed, drew objection and precipitated a lengthy and sometimes confusing wrangle. The upshot of it was a ruling by Justice Batten preventing counsel from thus using the document in aid of his cross-examination of this witness. And with that, counsel continued his cross-examination along different lines.
The testimony of Ms. Bunko-Ruys, and in particular her cross-examination, gave rise to the following grounds of appeal--the first two raised by Donald R., the third by Helen R., and the fourth by Donald W.--stating that Justice Batten had erred:
...in qualifying a therapist, Carol Bunko-Ruys, as an expert witness to give evidence concerning the behavioral characteristics of the sexually abused children.
...in limiting Defence Counsel's cross-examination of expert Carol Bunko-Ruys, in not allowing Defence the opportunity to present video tapes or transcripts of her interviews with the complainant children.
...in limiting cross-examination concerning the manner in which statements were taken from the infant witnesses and how evidence was elicited from them.
...by limiting Defence Counsel's cross-examination of Carol Bunko-Ruys and... by refusing the defence the opportunity to have the witness refresh her memory by having the witness review video tapes or transcripts of the witness's interviews with the child complainants.
I can see no merit in the first of these. I refer again to R. v. Marquard, and to R. v. Burns,  1 S.C.R. 656, simply to make the point that generally speaking there is a low threshold for qualification. I refer as well to R. v. B. (G.),  2 S.C.R. 30, to make the point that opinion evidence going to the behavioral characteristics of sexually abused children is generally admissible, a point reinforced in R. v. Marquard. Having regard for this, and for the education and experience of Ms. Bunko-Ruys, I do not think it can be said Justice Batten erred in qualifying the witness as she did.
And although little was made of this, I should say I do not think she erred in permitting the witness to express the opinions which were expressed. Nor do I think the witness went beyond her area of expertise. Indeed she was conscious of her own limitations, conscientious in not going beyond them, and fair, I might add, in the opinions she expressed. That is my assessment of the matter, and accordingly I can find nothing of concern in relation to the first ground of appeal. I might also add that Justice Batten found Ms. Bunko-Ruys to have been a very capable witness.
The other grounds of appeal--having to do with the cross-examination of Ms. Bunko-Ruys and with the video- tapes and so called "transcripts" of the interviews of the children--are more complex, but in my opinion they are ultimately no more telling against the conduct of the trial than the first.
As I understood the submission on appeal, the principal complaint in substance--issues of form aside--was that defence counsel had been unable to pursue an important line of inquiry with this witness, namely the propriety of the methods by which the interviews had been conducted, a line of inquiry directed toward the integrity of the interviews and the credibility and reliability of the testimony of the children. The point of the complaint seemed to have been this: The testimony of the children might have been discredited had counsel been able (i) to establish through Ms. Bunko-Ruys that the children had been interviewed in this manner or that, and (ii) to have then drawn from her the opinion they had been interviewed in an inappropriate manner, one calculated, wittingly or unwittingly, to induce them to have said this or that.
The ultimate flaw in this, the first leg of the submission, is that Ms. Bunko-Ruys was not qualified to express such an opinion. Her expertise did not extend that far. And even if she had been drawn out to this effect, what weight could have been given to her views? Very little I should think, especially when viewed in context.
With respect, it does not seem to me that counsel was intent on fully exploring the methods employed during Sergeant Dueck's interviews of the children with a view to attacking those methods--as distinct from exposing bits and pieces of the interviews and merely seeding doubts about the methods. Had it been thought the sergeant had used improper methods, and had implanted ideas in the minds of the children or induced them to say this or that, why was the matter not put to him? And why had there been no earlier effort to introduce the video-tapes for that purpose or to have him or someone else authenticate the "transcripts"? And finally, why was the matter not put to others, especially to Dr. Elterman who testified at the call of the defence and who had had much experience with such matters?
It was suggested that Justice Batten, in limiting the cross-examination of Ms. Bunko-Ruys, had in effect ruled out the admissibility of the video-tapes or transcripts, thus preventing them from being introduced for the purpose of attacking the integrity of the interviews. With respect, I think this is overdrawn. She was not about to have the "transcripts" go in through the back door--in piecemeal fashion and in the guise of having Ms. Bunko-Ruys refresh her memory--and she was not about to allow counsel to continue to cross-examine the witness along the line at issue and with the aid of the so-called "transcripts." That much is clear. But I do not think it can be said she ruled out the introduction of the video-tapes, or an authenticated version of the transcript, for the purpose of other attacks upon the methods employed in the conduct of the interviews, including a frontal attack by the defence.
In her ruling limiting the cross-examination of Ms. Bunko-Ruys, Justice Batten expressed the opinion, "unless I'm convinced by further argument," that the transcript could not be entered as evidence. Defence counsel then said this might "cause problems" down the road, adding that he intended to call an expert who had studied the case and come to some conclusions based upon seeing the tapes. Justice Batten responded by saying, "That may be a problem that we'll have...that we will come to." "Well yes," replied counsel, "Maybe I'm getting ahead of ourselves." As it turned out, this was the end of the matter, for it was not again raised.
For these reasons, then, I think the remaining grounds of appeal pertaining to the testimony of Ms. Bunko-Ruys must also fail.
Dr. Joanne Santa Barbara.
Dr. Santa Barbara, a child psychiatrist and assistant professor of psychiatry at McMaster University, was called by the Crown as an expert in "child development" and "the characteristics of abused children." The defence did not object to that. She was experienced in diagnosing and treating the conditions in children brought on by sexual abuse. She was also experienced in evaluating allegations of sexual abuse in the context of custody disputes in family courts, and she had been involved in the investigation and consideration of several instances of alleged ritualistic or satanic abuse. While not objecting to her testifying as an expert in child development and the characteristics of abused children, the defence did object to some of her testimony, particularly as it related to reportings of ritualistic abuse.
Dr. Santa Barbara began by testifying to the development and working of memory in children, commenting on their abilities at various ages to encode and recall information. She said children can have memories of salient events occurring at age three or four, especially of sexually abusive events, but that it is difficult for children under ten to place events in sequence and in time. She said, too, that young children are open to a degree of manipulation in recounting events, not in relation to the core of a registered memory but in respect of peripheral details which can easily be added to by suggestive or leading questions, noting that while children of a very young age may be indoctrinated with false accounts of a simple nature, they are not capable of concocting highly elaborate falsehoods. She went on to say that if a child is required soon after the happening of an event to repeatedly recount it, the memory of it may become consolidated and even more reliable, provided the account was elicited without implanted suggestions or erroneous leads, adding that recounting distressing events is at first emotionally difficult for children, but that they develop defensive mechanisms, and so repetitions may in time reflect boredom or annoyance, or become unemotional and flat.
Turning to the characteristics of abused children, she said "sexualization" was the strongest indicator of sexual abuse. Sexualization, she explained, is manifested in many ways, including inappropriate sexual play resistant to correction; frequent remarks about sexuality; advanced knowledge of, and interest, in the subject; initiating sexual contact with other children or adults; and so on. The longer and more often children are sexually abused, she observed, the more intense is their sexualization. Playing with dogs in a sexual way may indicate a very sexualized child, she noted, and running away at a very young age is indicative of something gone badly wrong in the home.
Presented with hypothetical examples of sexualized behaviours in children--resembling the behaviours in evidence--she expressed the view they were indicative of "long-standing serious abuse" or of "a pattern of long- standing sexualization." Intense sexualization early in a child's life at school is consistent, she said, with earlier serious abuse, and behaviour in a child of five, consisting of the frequent initiation of sexual contact with siblings and other children of similar age, is usually seen in the context of a pattern of long-standing sexualization.
Given her experience in the investigation and consideration of several incidents of reported ritualistic abuse, she was also asked about this subject. Justice Batten permitted her to testify about it, reserving her ruling on the admissibility of this evidence and directing the evidence be confined to the experience of the witness and not include opinions. And so Dr. Santa Barbara commented upon typical aspects of the phenomenon and its reporting, noting that reportings by children seem grounded in mis-perception or mis-interpretation, even trickery, rather than in imagination or conscious falsehood. She was quick to add, however, that people in the field are grappling with the phenomenon and that a great deal more remained to be learned.
Her testimony gave rise to two grounds of appeal-- taken by each of Donald R. and Donald W.--stating the trial judge had erred in law:
...in allowing Dr. Joanne Santa Barbara to give opinion evidence in the area of ritual sexual abuse after determining that the witness could not be qualified as an expert in that area.
...in allowing expert evidence to be admitted concerning the credibility of children's allegations of sexual abuse, which evidence contravened the rule against oath helping.
In the circumstances, little need be said of the first of these grounds of appeal. Counsel for Mr. R. confined his argument to the second, and counsel for Mr. W. made only passing comments on the first. Having made the point that Justice Batten was probably bound on the authority of R. v. Marquard to have disregarded the opinion evidence on this subject, counsel for Mr. W. went on to acknowledge that she may very well have done so, since she made no mention of it in her reasons for judgment, adding that the more important issue was that raised by the second or related ground of appeal.
As for the second ground, counsel for the appellants submitted that portions, if not all, of the opinion evidence of Dr. Santa Barbara should not have been received, because it was adduced for the purpose of bolstering the credibility of the children, contrary to the principle affirmed in R. v. Beland,  S.C.R. 398. The submissions varied. Counsel for Mr. R. took issue with the whole of the evidence of the witness, saying none of it was admissible for this reason. Counsel for Mr. W. objected to only portions of it, contending that Justice Batten should not have permitted the witness to testify that children of a very young age are incapable of concocting highly elaborate stories and that their reportings of ritualistic abuse appear to be grounded in mis-interpretation or mis- perception, rather than in conscious falsehood.
This issue falls to be addressed with the observations of Madame Justice McLachlin in R. v. Marquard in mind (at pp. 248-250):
It is a fundamental axiom of our trial process that the ultimate conclusion as to the credibility or truthfulness of a particular witness is for the trier of fact, and is not the proper subject of expert opinion.
This Court affirmed that proposition in R. v. Beland, supra, at p. 408, in rejecting the use of polygraph examinations as a tool to determine the credibility of witnesses:
From the foregoing comments, it will be seen that the rule against oath-helping, that is, adducing evidence solely for the purpose of bolstering a witness' credibility, is well grounded in authority.
A judge or jury who simply accepts an expert's opinion on the credibility of a witness would be abandoning its duty to itself determine the credibility of the witness.
Credibility must always be the product of the judge or jury's view of the diverse ingredients it has perceived at trial, combined with experience, logic and an intuitive sense of the matter: see R. v. B.(G) (1988), 65 Sask. R. 134 (C.A.), at p. 149, per Wakeling J.A., affirmed  2 S.C.R. 3. Credibility is a matter within the competence of lay people. Ordinary people draw conclusions about whether someone is lying or telling the truth on a daily basis. The expert who testifies on credibility is not sworn to the heavy duty of a judge or juror. Moreover, the expert's opinion may be founded on factors which are not in the evidence upon which the judge and juror are duty-bound to render a true verdict. Finally, credibility is a notoriously difficult problem, and the expert's opinion may be all too readily accepted by a frustrated jury as a convenient basis upon which to resolve its difficulties. All these considerations have contributed to the wise policy of the law in rejecting expert evidence on the truthfulness of witnesses.
On the other hand, there may be features of a witness's evidence which go beyond the ability of a lay person to understand, and hence which may justify expert evidence. This is particularly the case in the evidence of children. For example, the ordinary inference from failure to complain promptly about a sexual assault might be that the story is a fabricated afterthought, born of malice or some other calculated stratagem. Expert evidence has been properly led to explain the reasons why young victims of sexual abuse often do not complain immediately. Such evidence is helpful; indeed it may be essential to a just verdict.
For this reason, there is a growing consensus that while expert evidence on the ultimate credibility of a witness is not admissible, expert evidence on human conduct and the psychological and physical factors which may lead to certain behaviour relevant to credibility, is admissible, provided the testimony goes beyond the ordinary experience of the trier of fact. Professor A. Mewett describes the permissible use of this sort of evidence as "putting the witness's testimony in its proper context." He states in the editorial "Credibility and Consistency" (1991), 33 Crim. L.Q. 385, at p. 386:
The relevance of his testimony is to assist -- no more -- the jury in determining whether there is an explanation for what might otherwise be regarded as conduct that is inconsistent with that of a truthful witness. It does, of course, bolster the credibility of that witness, but it is evidence of how certain people react to certain experiences. Its relevance lies not in testimony that the prior witness is telling the truth but in testimony as to human behaviour. ...
There are concerns. As the court stated in R. v. J.(F.E.),[(1990), 53 C.C.C. (3d) 94, 74 C.R. (3d) 269, 36 O.A.C.348 (C.A.)] and R. v. C.(R.A.) (1990), 57 C.C.C. (3d) 522, 78 C.R. (3d) 390, the court must require that the witness be an expert in the particular area of human conduct in question; the evidence must be of the sort that the jury needs because the problem is beyond their ordinary experience; and the jury must be carefully instructed as to its function and duty in making the final decision without being unduly influenced by the expert nature of the evidence.
The conditions set out by Professor Mewett, reflecting the observations of various appellate courts which have considered the matter, recommend themselves as sound. To accept this approach is not to open the floodgates to expert testimony on whether witnesses are lying or telling the truth. It is rather to recognize that certain aspects of human behaviour which are important to the judge or jury's assessment of credibility may not be understood by the lay person and hence require elucidation by experts in human behaviour.