In 2015 in White Burgess Langille Inman v Abbott and Halibuton Co., 2015 SCC 23 the Supreme Court of Canada released a comprehensive decision on expert bias and how it relates to the admissibility and weight of expert evidence. At the threshold stage, expert evidence will only be inadmissible if the expert is unable or unwilling to discharge his or her duty to provide a fair, objective and non-partisan opinion. Once the threshold stage is met, any remaining concerns about an expert's compliance with his or her duty should be taken into account in the overall cost-benefit analysis at the gatekeeper stage. If the evidence passes both the threshold and gatekeeper stages, any residual concerns about bias should be reflected in the weight given to the expert opinion.

Lower courts are consistently applying the White Burgess framework. This sixth and final article in the series on expert evidence provides three examples of this.

In 2016 in R v Live Nation, 2016 ONCJ 223, the court considered all three stages of the White Burgess bias framework to determine whether to admit opinion evidence from the Crown's expert witnesses. Live Nation was being prosecuted for offences related to a stage collapse at an outdoor concert venue. At the voir dire, Live Nation sought to disqualify the Crown's expert engineers, arguing that they were biased because they were government employees who were closely involved in the investigation of the stage collapse. The court disagreed, ultimately allowing both experts to testify.

At the threshold stage of the bias inquiry, the court held that there was no evidence that the experts were unable or unwilling to fulfil their duty to provide a fair, objective and non-partisan opinion. The experts' employment relationship with the government and their involvement in the investigation did not automatically render their evidence inadmissible. As per White Burgess, the court reminded the parties that the test for inadmissibly is actual bias, not apparent bias and actual bias was not present in the case before it. At the gatekeeper stage of the bias inquiry, the court held that a cost-benefit analysis favoured admitting the expert evidence. The collapse of the stage was the central issue in the case and it required technical evidence. There was no prejudice to the trial process in admitting the evidence as it would not consume an undue amount of time or be distracting or misleading. The court concluded that any residual bias would be considered during the trial, when weighing the experts' evidence.

In 2017 in R v Livingston, 2017 ONCJ 645, the court's inquiry into whether to admit opinion evidence from the Crown's expert witness ended at the gatekeeper stage. This was a voir dire for the gas plant scandal in which the chief of staff to the former Ontario premier was accused of wiping computer hard drives in order to destroy government records. The accused sought to disqualify the Crown's computer systems expert on the basis that he was too closely involved with the Crown's gas plant investigation and the court agreed. Although the court was careful not to impugn the personal integrity of the expert, it nonetheless found that he was unable to discharge his duty to the court to provide a fair, objective and non-partisan opinion due to the role he played during the criminal investigation.

Although threshold admissibility is not an onerous test, the court held that this was one of those rare cases where the expert was obviously very biased. The expert took on what the judge referred to as "an extensive, active and proactive" role in the Crown's investigation of the gas plant scandal. He participated in numerous meetings with investigators, recommended charges against the accused, and provided investigators with strategic and legal advice in their efforts to mount a case. The judge ultimately likened the expert's behaviour to that of a partisan police officer.

Finally, in 2017 in Gunawardena v Bruff-Murphy, 2017 ONCA 502 the Court of Appeal reviewed a trial judge's interpretation of the bias framework in deciding to admit opinion evidence from the defendant's expert witness. The action arose from a motor vehicle accident. During the course of the trial, the judge qualified the defendant's expert psychiatrist despite serious concerns about his independence, citing the very high threshold for excluding expert testimony as per White Burgess. The Court of Appeal held that the trial judge erred in admitting the expert psychiatrist's opinion evidence and ordered a new trial.

The Court of Appeal found that the trial judge erred in principle in failing to appropriately exercise his gatekeeper function and instead considered himself limited by the threshold stage. In this case, the risks of admitting the psychiatrist's testimony clearly outweighed any benefits because the expert had become an advocate by hunting for discrepancies between the plaintiff's statements and her medical records while denying her the opportunity to explain these discrepancies. The court reasoned that this was the kind of analysis is performed by a lawyer during cross-examination. If not excluded during the initial qualification stage, the court found that the trial judge ought to have taken action later on when it became clear during the expert's testimony that he was biased. The trial judge's failure to do so resulted in trial fairness being irreparably compromised.

R v Live Nation, R v Livingston, and Gunawardena v Bruff-Murphy show that while threshold admissibility is not an onerous test under which an expert can only be disqualified if actual bias is demonstrated, evidence should be excluded as part of the gatekeeper analysis if the risk of expert bias outweighs the potential benefits of the opinion evidence. This becomes a particular concern where the expert has become an advocate for the party who retained her.

Jennifer Hunter is a partner in the Toronto office of Lerners LLP, specializing in health law and insurance defence. This article was written with the valuable assistance of Julia Boddy, articling student in the Toronto office.

This article originally appeared on The Lawyer's Daily website published by LexisNexis Canada Inc.

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