Over the past year or so, a series of Canadian decisions have caused lawyers, judges and legal commentators to refocus on the issue of expert evidence in litigation. From the interaction of expert witnesses with the people who pay their fees, to concerns with the quality and usefulness of the evidence they provide, our system is getting an overhaul.
This discussion will look at efforts to ensure that only helpful expert evidence finds its way into litigation. This is not intended to be a thorough review of the law of expert evidence. Instead, its goal is to provide claims handlers with updated suggestions for considering expert reports when presented by claimants and their lawyers. However, since claims are ultimately disposed of (either by settlement or trial) with reference to the proof being offered and how it might play out in a courtroom, an understanding of some of these recent developments is essential to effective claims handling. Knowing when to raise questions about the quality of expert opinions being put forward by the other side can play a major role in the proper assessment and reserving of a given claim. Strategically communicated, your response to the claimant's expert report can also have a profound effect upon a successful settlement or denial of a claim.
The Basics of Expert Evidence
The healthy skepticism that gets claims handlers and their defence counsel asking the right questions is a product of what has been described as the court's "gatekeeping" role when considering expert evidence. A few basics will serve as a springboard to this part of the discussion.
First, the core purpose of expert evidence in litigation is to help judges and juries make sense of aspects of our world that are highly complex when those things are part of what has given rise to a claim. An obvious example is a bodily injury. A simple broken leg can become highly complex when we need to know how it is to be treated, if surgery is required and its long term effects in terms of pain, gait abnormalities and other forms of disability. These are not matters within common knowledge and clearly require the assistance of an expert in medicine (sometimes several) to sort out. The courts have embraced the value of expert witnesses as providers of necessary assistance in understanding scientifically or technologically complex fact situations.
Next, fundamental to the notion of using expert witnesses, is that they are to assist the court. In order to do so effectively, they must be objective and impartial. This creates a certain amount of tension in the presentation of expert evidence, since it is almost always put forward by one of the combatants in the litigation. Expert witnesses are very seldom court-appointed. In spite of the fact that their fees are paid by litigants, experts are expected to give objective and unbiased opinions about the matter upon which they are asked to comment and its application to the circumstances of the claim.
Finally, the specific evidence given needs to actually be helpful to the court in making its findings of fact and rendering a decision. This requires that expert evidence actually reflects established scientific or technical knowledge. It also means that the expert opinion needs to be necessary in order for the court to make its decision.
Analysis of an opposing expert's opinion will always include careful consideration of the factual assumptions upon which it is based and the quality of any statistical analysis undertaken. These remain important questions and have not changed as a result of recent case law developments. The newer decisions open new fronts on inquiry and challenge which, if successful, can have a profound impact on claim outcomes.
The need for objectivity and scientific validity are at the heart of important recent Canadian decisions.
Independence, Impartiality and Bias
In 2015, the Supreme Court of Canada called for renewed emphasis on ensuring the independence and impartiality of expert opinions being placed before the courts. In WBLI v. Abbott and Haliburton  2 SCR 182 Justice Cromwell, writing for the unanimous court described the problem:
 There have been long-standing concerns about whether expert witnesses hired by parties are impartial in the sense that they are expressing their own unbiased professional opinion and whether they are independent in the sense that their opinion is the product of their own, independent conclusions based on their own knowledge and judgment: see, e.g., G.R. Anderson, Expert Evidence (3rd ed. 2014), at p. 509; S.N. Lederman, A.W. Bryant and M.K. Fuerst, The Law of Evidence in Canada (4th ed. 2014), at p. 783. As Sir George Jessel, M.R., put it in the 1870s, "[u]ndoubtedly there is a natural bias to do something serviceable for those who employ you and adequately remunerate you. It is very natural, and it is so effectual, that we constantly see persons, instead of considering themselves witnesses, rather consider themselves as the paid agents of the person who employs them": Lord Abinger v. Ashton (1873), L.R. 17 Eq. 358, at p. 374.
 Recent experience has only exacerbated these concerns; we are now all too aware that an expert's lack of independence and impartiality can result in egregious miscarriages of justice: R. v. D.D., 2000 SCC 43,  2 S.C.R. 275, at para. 52. As observed by Beveridge J.A. in this case, The Commission on Proceedings Involving Guy Paul Morin: Report (1998) authored by the Honourable Fred Kaufman and the Inquiry into Pediatric Forensic Patho9logy in Ontario: Report (2008) conducted by the Honourable Stephen T. Goudge provide two striking examples where "[s]eemingly solid and impartial, but flawed, forensic scientific opinion has played a prominent role in miscarriages of justice": para. 105. Other reports outline the critical need for impartial and independent expert evidence in civil litigation: ibid., at para. 106; see the Right Honourable Lord Woolf, Access to Justice: Final Report (1996); the Honourable Coulter A. Osborne, Civil Justice Reform Project: Summary of Findings & Recommendations (2007).
Justice Cromwell went on to describe a process for determining how best to deal with allegations that an expert opinion is biased or otherwise lacks the necessary attributes of impartiality and independence. Less important to the purpose of this discussion are the specific steps to be followed by the court in considering attacks on impartiality and independence. More important are the potential remedies:
- The opinion evidence may be ruled inadmissible and therefore never considered by the judge or jury. If it can be established that by reason of interest in the outcome of the litigation or assumption of the role of an advocate for a party, as examples, an expert is unable or unwilling to fulfill the primary duty of impartiality described above, the opinion may be excluded entirely. In other words, the expert evidence is never heard by the court. Such instances will be relatively rare.
- The opinion evidence may be heard by the judge or jury but subjected to questions of weight. Concerns that fall short of establishing that the expert lacks the ability or willingness to fulfill the primary duty may be taken into account in deciding how much weight to attach to the opinion evidence. Issues such as the frequency of testimony for one side or another and relationships with the party retaining the expert that do not entirely rule out objectivity can thus still play a role in considering the opinion evidence, and may ultimately result in it receiving little or no weight in the court's decision.
The take away for all of us is that our assessment of an expert must include consideration of whether the expert him or herself is being truly impartial and independent in rendering the opinion.
- Does the expert have a relationship with the opposing party or an interest in the outcome of the litigation that is preventing him or her from fulfilling the primary duty to the court?
- Is the expert assuming the role of advocate in promoting the position of the other side rather than assisting the court in making sense of scientific or technical information?
Proper Qualifications of Experts and the Undesirability of "Junk Science"
Another aspect of expert evidence that has received recent close attention from Canadian Courts is the importance of only scientifically reliable opinions, given by witnesses properly qualified to give them, being placed before the courts. The previously mentioned Supreme Court of Canada decision in WBLI (supra) provides a starting point:
[16} Since at least the mid-1990s, the Court has responded to a number of concerns about the impact on the litigation process of expert evidence of dubious value. The jurisprudence has clarified and tightened the threshold requirements for admissibility, added new requirements in order to assure reliability, particularly or novel scientific evidence, and emphasized the important role that judges should play as "gatekeepers" to screen out proposed evidence whose value does not justify the risk of confusion, time and expense that may result from its admission.
In this context as well, there is a renewed emphasis on ensuring only appropriate (i.e. helpful and reliable) opinion evidence be heard from witnesses properly qualified to give it. Where expert evidence falls short of meeting these requirements, the following remedies are available:
- Where the opinion expressed is not within the scope of the witness' expertise, his or her testimony is inadmissible.
- Expert testimony which is based upon novel science or uses science for a novel purpose and which is unreliable as a result (i.e. so called "junk science") will not be admitted.
Whether the expert is remaining within the scope of his or her expertise will be a question of fact based upon analysis of the witness' specific education, experience and the nature of the opinion proffered.
The rule that "junk science" is inadmissible requires the court to consider both the context in which the opinion is being presented and whether the scientific underpinnings of the expert evidence have been widely accepted in the courts as scientific. If the science or the specific purpose for which it is being used is novel, the court must then go on to consider its reliability.
The December 2015 decision of Justice Stack of the Supreme Court of Newfoundland and Labrador dealt with these issues in Anderson v. Canada (Attorney General) 2015 CanLII 83951 (NLSCRD). In considering the novel applications of social and psychological science to the effects of abuse in the residential schools, Stack J found that specific expert opinion lacked the requisite reliability to render it admissible. The evidence was therefore entirely excluded. While the court's analysis was specific to the nature of the expert evidence before it, the mechanics of the decision are perhaps less important than the clear signal from the Canadian judiciary that this aspect of expert testimony will be subjected to greater scrutiny going forward.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.