Barrister and Solicitor
Legal Writing and Research
Evidence - Experts
Evidence - Hearsay - Res Gestae Exception
Moore v Getahun (Ont CA, 2015)
In this case the Court of Appeal made the following salutory comments on the nature of expert evidence, in the context of a dispute over whether counsel could review draft expert reports before final preparation and disclosure:
 Expert evidence is a significant and controversial feature of modern civil litigation. It constitutes an exception to the rule that witnesses may only testify as to facts, not opinions, and that it is the exclusive prerogative of the trier of fact to draw inferences from proven facts. The expert evidence exception operates where specialized knowledge is required to determine the implications of the bare facts and where the trier of fact is not competent to draw the necessary inferences unaided: R. v. Mohan, 1994 CanLII 80 (SCC),  2 S.C.R. 9, at p. 23; R. v. Abbey, 2009 ONCA 624 (CanLII), 246 C.C.C. (3d) 301, at para. 94.At paras 67-78 the court also considers when such drafts and ancillary material are protected by litigation privilege and when, alternatively, they must be disclosed in the litigation process.
 Expert evidence has become more significant with the explosion of scientific knowledge and technical innovation. Many cases have been described as a “battle of experts”. Medical negligence cases are a prime example. The trier of fact requires the assistance of expert witnesses to decide issues pertaining to the standard of care, causation and prognosis.
 The use of expert evidence poses difficult issues that have been the focus of consideration in civil justice reform. How do we control the added costs associated with the explosion of expert witnesses? How do we ensure that a party has a fair opportunity to challenge an adverse expert witness? How do we ensure that expert witnesses offer an unbiased scientific or technical opinion based upon their training and expertise, rather than act as “hired guns” who present unbalanced opinions unduly favouring the party that retains them?
[paras 36-40 contain a useful summary of recent Rule 53 amendments relating to the use of expert evidence]
 I now turn to the law. I disagree with the trial judge’s statement that the 2010 amendments to rule 53.03 introduced a “change in the role of expert witnesses”.
 As I read the amendments and the Osborne Report recommendations, the changes were intended to clarify and emphasize the existing duties of expert witnesses. I agree with Lederman J.’s statement in Henderson v. Risi, 2012 ONSC 3459 (CanLII), 111 O.R. (3d) 554 (S.C.), at para. 19, that these changes represent a restatement of the basic common law principle that it is the duty of an expert witness “to provide opinion evidence that is fair, objective and non-partisan.” Those common law duties were summarized in an often cited passage from National Justice Compania Naviera S.A. v. Prudential Assurance Co. Ltd. (“The Ikarian Reefer”),  2 Lloyd's Rep. 68, at p. 81 (Eng. Q.B. Comm.), rev'd on other grounds but endorsed on this point,  1 Lloyd's Rep 455 (Eng. C.A. Civ.), at p. 496:
1. Expert evidence presented to the Court should be, and should be seen to be, the independent product of the expert uninfluenced as to form or content by the exigencies of litigation [citation omitted].The 2010 amendments to rule 53.03 did not create new duties but rather codified and reinforced these basic common law principles.
2. An expert witness should provide independent assistance to the Court by way of objective unbiased opinion in relation to matters within his expertise [citation omitted]. An expert witness… should never assume the role of an advocate.
 The changes suggested by the trial judge find no support in the various reviews and studies on civil justice reform to which we have been referred. The Honourable Coulter Osborne certainly shared the trial judge’s aspiration for a regime that fosters unbiased expert evidence, yet there is no suggestion in his report that the solution could be found by altering the long-standing practice of counsel reviewing draft reports.
 While some judges have expressed concern that the impartiality of expert evidence may be tainted by discussions with counsel (see the cases cited below, at para. 72), banning undocumented discussions between counsel and expert witnesses or mandating disclosure of all written communications is unsupported by and contrary to existing authority: see Maras v. Seemore Entertainment Ltd., 2014 BCSC 1109 (CanLII),  B.C.W.L.D. 4470, at para. 90 (“[c]ounsel have a role in assisting experts to provide a report that satisfies the criteria of admissibility”); Surrey Credit Union v. Willson (1990), 1990 CanLII 1983 (BC SC), 45 B.C.L.R. (2d) 310 (S.C.), at para. 25 (“[t]here can be no criticism of counsel assisting an expert witness in the preparation of giving evidence”). In Medimmune Ltd. v. Novartis Pharmaceuticals UK Ltd. & Anor,  EWHC 1669 (Pat.), the court pointed out, at para. 110, that in some highly technical areas such as patent law, expert witnesses “require a high level of instruction by the lawyers” which may necessitate “a high degree of consultation” involving “an iterative process through a number of drafts.”
 As the court in Medimmune noted, at para. 111, “this process entails a risk of loss of objectivity on the part of the expert”. However, the independence and objectivity of expert witnesses is fostered under existing law and practice in a number of ways.
 First, the ethical and professional standards of the legal profession forbid counsel from engaging in practices likely to interfere with the independence and objectivity of expert witnesses. I attach as an Appendix to these reasons The Advocates’ Society’s Principles Governing Communications with Testifying Experts, which provides a thorough and thoughtful statement of the professional standards pertaining to the preparation of expert witnesses. Principle 3 states:
In fulfilling the advocate’s duty to present clear, comprehensible and relevant expert evidence, the advocate should not communicate with an expert witness in any manner likely to interfere with the expert’s duties of independence and objectivity. To the same effect, The Holland Group’s position paper includes, at p. 4, its opinion “that it is inappropriate for counsel to persuade or attempt to persuade experts to articulate opinions that they do not genuinely hold, and that it is of paramount importance that the expert genuinely believes the opinion that he or she articulates both in the expert report and in the witness box.”
 In Medimmune, at para. 111, the court emphasized that it is “crucial that the lawyers involved should keep the expert’s need to remain objective at the forefront of their minds at all times.”
 Second, the ethical standards of other professional bodies place an obligation upon their members to be independent and impartial when giving expert evidence: see Guideline: The Professional Engineer as an Expert Witness (Toronto: Association of Professional Engineers of Ontario, September 2011); the Actuarial Standards Board’s Standards of Practice (Ottawa: Canadian Institute of Actuaries, October 2014); the Canadian Institute of Chartered Business Valuators’ Code of Ethics (Toronto: Canadian Institute of Chartered Business Valuators, 2012), Standard No. 110: Valuation Reports (Toronto: Canadian Institute of Chartered Business Valuators, 2009) and Standard No. 310: Expert Reports (Toronto: Canadian Institute of Chartered Business Valuators, 2010). Further, pursuant to the Rules of Civil Procedure, every expert witness is reminded of the duty imposed by rule 4.1.01 to be objective and impartial when signing the acknowledgment of expert’s duty mandated by rule 53.03(2.1).
 Third, the adversarial process, particularly through cross-examination, provides an effective tool to deal with cases where there is an air of reality to the suggestion that counsel improperly influenced an expert witness. Judges have not shied away from rejecting or limiting the weight to be given to the evidence of an expert witness where there is evidence of a lack of independence or impartiality. In Medimmune, at para. 111, the court noted that “partisan expert evidence is almost always exposed as such in cross-examination, which is likely to reduce, if not eliminate, the value of the evidence to the client’s case”; see also Alfano v. Piersanti, 2012 ONCA 297 (CanLII), 291 O.A.C. 62, at paras. 106-120.
 I agree with the submissions of the appellant and the interveners that it would be bad policy to disturb the well-established practice of counsel meeting with expert witnesses to review draft reports. Just as lawyers and judges need the input of experts, so too do expert witnesses need the assistance of lawyers in framing their reports in a way that is comprehensible and responsive to the pertinent legal issues in a case.
 Consultation and collaboration between counsel and expert witnesses is essential to ensure that the expert witness understands the duties reflected by rule 4.1.01 and contained in the Form 53 acknowledgment of expert’s duty. Reviewing a draft report enables counsel to ensure that the report (i) complies with the Rules of Civil Procedure and the rules of evidence, (ii) addresses and is restricted to the relevant issues and (iii) is written in a manner and style that is accessible and comprehensible. Counsel need to ensure that the expert witness understands matters such as the difference between the legal burden of proof and scientific certainty, the need to clarify the facts and assumptions underlying the expert’s opinion, the need to confine the report to matters within the expert witness’s area of expertise and the need to avoid usurping the court’s function as the ultimate arbiter of the issues.
 Counsel play a crucial mediating role by explaining the legal issues to the expert witness and then by presenting complex expert evidence to the court. It is difficult to see how counsel could perform this role without engaging in communication with the expert as the report is being prepared.
 Leaving the expert witness entirely to his or her own devices, or requiring all changes to be documented in a formalized written exchange, would result in increased delay and cost in a regime already struggling to deliver justice in a timely and efficient manner. Such a rule would encourage the hiring of “shadow experts” to advise counsel. There would be an incentive to jettison rather than edit and improve badly drafted reports, causing added cost and delay. Precluding consultation would also encourage the use of those expert witnesses who make a career of testifying in court and who are often perceived to be hired guns likely to offer partisan opinions, as these expert witnesses may require less guidance and preparation. In my respectful view, the changes suggested by the trial judge would not be in the interests of justice and would frustrate the timely and cost-effective adjudication of civil disputes.
The court continued to comment as follows on the evidentiary res gestae hearsay exception:
 The appellant submits that the trial judge erred in her application of the res gestae exception to the hearsay evidence rule. The res gestae exception allows a court to admit, for the truth of their contents, certain utterances which would otherwise be classified as hearsay on the grounds that the contemporaneous circumstances make the utterances reliable and less prone to misinterpretation. The three categories of utterances that may be properly characterized as part of the res gestae are (i) “declarations of bodily and mental findings and conditions”, (ii) “declarations accompanying and explaining relevant acts” and (iii) “spontaneous exclamations”: Bryant, Lederman and Fuerst, at para. 6.299..
 While I agree that the trial judge misused the label “res gestae”, I am not persuaded that she made inappropriate use of hearsay evidence or that any error she made had an impact on the outcome of this trial.
 As I have noted, the trial judge referred to res gestae in relation to two pieces of evidence – first, in relation to the report written by Dr. Orsini giving his opinion on the issues of standard of care and causation, and second, in relation to the statements made by Dr. Orsini to the respondent’s father commenting adversely on the appellant’s treatment of the respondent. In both instances, she clearly stated that she was not admitting the hearsay evidence for its truth, but only as part of the narrative.
 The res gestae doctrine operates as an exception to the hearsay rule and allows a court to admit certain utterances for their truth. The res gestae doctrine has no application to the admission of evidence as part of the narrative. I note, however, that the trial judge’s error is relatively common: see Bryant, Lederman and Fuerst, at paras. 6.300-6.301. In my view, in this case, it was a harmless error of nomenclature rather than substance.