10 Aug White Burgess Langille Inman v. Abbott 2015 SCC
Up until this decision, conflicting caselaw existed about when a trier of fact should consider the independence and impartiality of an expert. Some courts ruled that it should be considered at the threshold admissibility stage, while others held that it should only be considered in the weight given to the evidence stage. In April, 2015, the Supreme Court of Canada clarified that when determining the admissibility of expert evidence, the independence and impartiality of an expert witness should be addressed at the threshold admissibility stage, thereby providing guidance to the legal framework for expert opinion evidence established by the Supreme Court in R. v. Mohan  2 S.C.R. 9.
This action was one of professional negligence brought by a group of shareholders against their former auditors. The shareholders had hired a new accounting firm (Grant Thornton) who identified problems with the work of the former auditors. The shareholders retained an expert, who also worked at Grant Thornton, although in a different office. The defendant challenged the independence of the plaintiffs’ expert on the basis that her firm would be vulnerable to litigation if her evidence was not accepted by the court and so she lacked independence.
Writing for the Court, Justice Cromwell clarified the two-stage test for admissibility of expert evidence as follows:
At the first stage, the evidence must meet four threshold requirements of admissibility as set out in Mohan:
2. Necessity in assisting the trier of fact;
3. Absence of an exclusionary rule; and
4. Properly qualified expert.
If the evidence is considered admissible, the second stage of the analysis allows the judge to exclude the evidence based on a cost-benefit analysis of whether it “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.”
Concerns about an expert’s independence and impartiality should be addressed at the threshold admissibility stage. This standard is not onerous; is the expert aware of his/her primary duty to the court and able and willing to carry it out? The expert’s testimony or attestation in a report or otherwise will be sufficient to meet this threshold. The onus then shifts to the other party to show there is a realistic concern that the expert is unwilling or unable to comply with his or her duties.
The Supreme Court provided some guidance about what could render evidence inadmissible. For example, more than an appearance of bias or the existence of an employment relationship is necessary for expert evidence to be inadmissible. The Court noted that factors that cause concern to be if the expert has a direct financial interest in the outcome of the litigation or if there is a familial relationship between the expert and a party.
Ultimately, the test is “whether the expert’s opinion would not change regardless of which party retained him or her.” Any peripheral concerns about an expert’s impartiality can be addressed at cost-benefit stage.
In this case, the expert testified that she understood and was able to comply with her duty to the Court, thereby satisfying the threshold qualification. The opposing party was unable to provide a satisfactory basis to exclude her evidence. As such, the Court concluded that the expert’s evidence was admissible.
This decision emphasized the importance of experts knowing their duty to the Court to give fair, objective and non-partisan opinion evidence. If a Court is not satisfied that an expert has discharged this duty, then their evidence becomes inadmissible.