Expert Evidence: Passing the Acid Test of Independence and Impartiality

On April 30, 2015, the Supreme Court of Canada released its decision in White Burgess Langille Inman v. Abbott and Haliburton ("Burgess"). While the underlying action concerns a professional negligence claim commenced by shareholders against the corporation's former auditors, the Supreme Court's decision is relevant to any litigation where parties intend to rely on expert evidence.

In Burgess, the shareholders retained an accounting firm, the Kentville office of Grant Thornton, to perform various accounting tasks. As a result of Grant Thronton's work, the shareholders commenced a professional negligence action against the former auditors of the company, alleging that their failure to apply generally accepted auditing and accounting standards caused financial loss to the shareholders.
The auditors brought a motion for summary judgment, seeking to have the shareholders' action dismissed. In response, the shareholders retained a forensic accounting partner who, in her findings, found that the auditors had not complied with their professional obligations to the shareholders.

While the motion judge found the expert's evidence to be inadmissible, the majority of the Court of Appeal overturned this decision, finding that the test adopted by the judge in excluding her evidence was wrong in law.

The Supreme Court upheld the Court of Appeal's decision and dismissed the appeal. In so doing, the Court provided a detailed summary of an expert's duty to the court and refined the test governing the admissibility of expert evidence.

The Court emphasized that an expert must be willing, and has a duty, to provide fair, objective and non-partisan opinion evidence to the court. The "acid test" is whether the expert's opinion would not change regardless of which party retained him or her. Identified by the Court as the "threshold admissibility requirement", the Court stated that this threshold will typically be met where the expert's attestation or testimony recognizes and accepts this duty.

Nevertheless, where the opposing party calls the expert's impartiality and independence into question, the Court held that the onus will remain on the party looking to introduce the expert evidence to meet the threshold admissibility requirement. However, the Court emphasized that the threshold requirement is not onerous and it would be "quite rare" for expert evidence to be ruled inadmissible for failing to meet it.

Further, in considering the framework for the admissibility of evidence generally, the Court found it was appropriate to consider issues of independence and impartiality as a part of determining whether an expert is a properly qualified expert.

Where the proponent establishes the threshold requirements of admissibility, the Court noted that there is a second "discretionary gatekeeping step" whereby the trial judge must decide whether the expert evidence is sufficiently beneficial to the trial process to warrant its admission despite the potential harm that may flow from its admission.

Overall, while Burgess seems to raise the bar when introducing expert evidence, the Court did state that finding expert evidence inadmissible at the threshold stage should only occur in the "clearest of cases" where the expert is unable or unwilling to provide fair, objective and non-partisan advice.