In an adversarial environment, lawyers on both sides will endeavor to put their best foot forward on behalf of their clients.  However, experts are always expected to provide the court with unbiased, non-partisan opinion evidence. Recent judicial decisions have helped identify situations of bias and helped to clarify circumstances when the court may choose to include or exclude an expert’s evidence. 

The starting point for any analysis as to the role and duty of experts can be found at 4.1.01 of the Rules of Civil Procedure (Ontario), which reads: “It is the duty of every expert engaged by or on behalf of a party to provide evidence in relation to a proceeding under these rules, to provide opinion evidence that is fair, objective and non-partisan; to provide opinion evidence that is related only to matters that are within the expert’s area of expertise; and to provide such additional assistance as the court may reasonably require to determine a matter in issue.”  Most importantly, this duty “prevails over any obligation owed by the expert to the party by whom or on whose behalf he or she is engaged.”

The court in the recent case of Daggitt v. Campbell 2016 ONSC 2742, in obiter dicta, analyzed whether an expert hired by defence counsel should be permitted to conduct a defence medical examination. One of the starting points of this analysis was to look into previous judicial decisions where this expert has testified before the courts. In previous cases, it was found that this expert’s report and testimony was not “of a psychiatric nature,” but instead was presented under the “guise of expert medical testimony.”  Here, the courts indicate that the main consideration is to ensure a fair trial, through minimizing the potential for a miscarriage of justice which might occur when an expert is biased, particularly before a jury.

In another recent case, Mamado v Fridson, 2016 ONSC 4080, the defendants brought what is commonly known as a “threshold motion” to determine whether the plaintiff suffered a serious and permanent impairment of an important physical, mental or psychological function as a result of injuries sustained in a motor vehicle accident.  The court had various issues with the experts retained by defence counsel. 

With respect to the physiatrist, the court found that she had misread the plaintiff’s pre-accident medical history, was unable to remember how long she spent reviewing the plaintiff’s medical brief and preparing the report, and was also “indignant” when it was revealed that her income in the previous year, between $450,000-$470,000, was almost entirely from assessments performed for defence lawyers and insurance companies, and that she had only testified on behalf of a plaintiff once, when that plaintiff happened to be her patient. The other expert, a psychiatrist, admitted in cross-examination that he would “view anyone as suspicious who may be injured in an accident and end up before him for a medical-legal assessment” and he also misread the plaintiff’s pre-accident medical history.  This expert also derived half of this time and two-thirds of his income of roughly $400,000 from doing medical-legal work on behalf of defendants.  Both experts in this case are of the view that, despite the fact that their livelihoods depend on a certain client base, they can be entirely neutral and this does not influence them in any way.  The court instead found that their core evidence was overall supportive of the plaintiff’s claim.

The Supreme Court of Canada in White Burgess Langille Inman v. Abbott and Haliburton Co., [2015] 2 SCR 182 provided some much needed insight as to the admissibility of expert opinion evidence.  The first step is that the threshold requirements of admissibility must be established.  The four factors are set out in R. v. Mohan [1994] 2 SCR 9: relevance, necessity, absence of an exclusionary rule and a properly qualified expert.  If these threshold requirements are not met, evidence should be excluded.  The trial judge must then determine whether the evidence which meets the first step is “sufficiently beneficial to the trial process to warrant its admission despite the potential harm to the trial process that may flow from the admission of the expert evidence.” 

The overriding factor is that experts must be prepared to present an opinion that is impartial, independent and unbiased. This means that an expert’s evidence would not change depending on who hired him or her, but these concepts must be examined by taking into account the realities of adversarial litigation.  The court also provided instruction as to the concept of apparent bias: the question to be answered is not whether “a reasonable observer would think that the expert is not independent”, but whether “the relationship or interest results in the expert being unable or unwilling to carry out his or her primary duty to the court to provide fair, non-partisan and objective assistance.”