Supreme Court Of Canada Clarifies Test For Admissibility Of Expert Evidence

On April 30, 2015, the Supreme Court of Canada released its decision in White Burgess Langille Inman v Abbott and Haliburton.1 With this decision it is now clear that an expert may be qualified to give expert evidence despite having a pre-existing relationship with one or both of the litigants.

In Burgess, the plaintiff shareholders brought a professional negligence claim against the company's former auditor. The plaintiffs commenced the action after they retained a different accounting firm to perform various tasks, the results of which revealed several errors in the defendant auditors' prior work. The defendant auditors brought a motion for summary judgment and, in response, the plaintiffs retained a forensic accountant to prepare a report on her findings.

The defendant challenged the admissibility of this evidence on the basis that the expert who had been retained was a partner at the firm that had revealed the defendant's alleged errors. The defendant argued that the action came down to a battle of opinions between accounting firms and, because the expert's firm could be held liable if its approach was not accepted by the court, the expert had a personal financial interest in the outcome of this litigation.

Lower court decisions

The Nova Scotia Supreme Court agreed with the defendant's position and struck out the expert's affidavit. The court held that to be admissible an expert's evidence "must be, and must be seen to be, independent and impartial."2 The court concluded that in this instance, the expert's evidence did not meet this threshold requirement for admissibility because she had a personal interest in the outcome of this litigation.

The majority of the Court of Appeal for Nova Scotia concluded that the motions judge erred in excluding the expert's evidence. Writing for the court, Beveridge J.A. held that although the court has discretion to exclude expert evidence due to actual bias or partiality, the motions judge erred in holding that an expert "must be, and must be seen to be, independent and impartial."3

Supreme Court decision

On appeal, the Supreme Court of Canada took the opportunity to clarify the test for the admissibility of expert evidence. At the outset, the court stated there have long been concerns about whether expert witnesses are impartial in the sense of expressing their own unbiased opinions and whether they are independent in the sense that their opinion is based on their own knowledge and judgment.4

The...