Expert evidence plays an integral role in personal injury cases. Experts provide opinions and educate the Court on issues that fall outside the knowledge and expertise of the layperson. The use of expert witnesses has also been the subject of significant judicial scrutiny, particularly in terms of their independence and relationship with the lawyer that hired them.
The landmark decision in Moore v. Gethaun established clear guidelines on these issues, affirming that lawyers can consult with expert witnesses but must ensure that the opinions remain independent.
Subsequent cases, such as Salamaszynski and Wright have continued to shape the legal landscape on expert evidence. These cases demonstrate how the courts have applied Moore v. Gethaun in cases involving expert witnesses.
Moore v. Gethaun 2015 ONCA 55
This was a medical malpractice case following complications arising from treatment for a wrist injury. During the trial, there were concerns raised by the defendant about the expert evidence and the extent to which the expert report had been reviewed and edited by the plaintiff’s lawyer. Justice Wilson ruled that lawyers should not discuss draft expert reports with witnesses, arguing that such interactions risk undermining expert independence. This decision raised a great deal of chatter in the legal community and the decision was appealed.
In a landmark decision, the Court of Appeal overturned the trial ruling and stated the following with respect to expert witnesses:
- Lawyers can review expert reports – it is permissible for lawyers to discuss reports with experts to clarify issues and ensure that the reports are compliant with the law.
- Expert independence must be maintained – while consultation is allowed, the opinion of the expert must be their own.
- Draft reports are allowed – the court rejected the idea that draft reports should not be reviewed or discussed, recognizing that such collaboration enhances clarity and quality.
- Demanding Production Disallowed – Absent a factual foundation to support reasonable suspicion that counsel improperly influenced the expert, a party should not be allowed to demand production of draft reports or interactions between counsel and the expert.
Wright v Detour Gold Corporation 2016 ONSC 6807
In this case, the defendant retained an expert to provide an opinion on the defendant’s duty to disclose information to the public. The expert retained by defence counsel retained his counsel, Skylaw PC, to conduct legal research into the issue.
The Plaintiff brought a motion for production of the expert’s file arguing that the involvement of independent counsel interfered with the expert’s impartiality and duty to the Court.
In response to what was described as a “bombastically hyperbolic submission”. Justice Perell said that “what occurred in this case, if anything, is to be encouraged not discouraged”. Justice Perell said that the assistance of independent counsel served to enhance the expert’s independence and impartiality as opposed to risking it.
Justice Perell found that the refusal of the defendants to produce correspondence and drafts of the affidavit during discovery were proper because they were covered by litigation privilege and there was no factual foundation to support reasonable suspicion that counsel improperly influenced the expert in this case.
Salamaszynski v. Michael Garron Hospital 2023 ONSC 704
In this medical malpractice case, the Plaintiff sought production of the defendant’s expert’s instructing letter, emails and memos detailing conversations between the expert arguing that production should be ordered because the defence expert was asked to assume facts that had not been anticipated in the case to date.
Justice Jolly stated that in order for production to be ordered, the Plaintiff must show that there was evidence that might support a reasonable suspicion that counsel improperly influenced the expert. Ultimately, Justice Jolly found no such conduct and found that the defendant had met their obligations under the Rules and had not waved litigation privilege by serving the expert report.
The evolution of expert witness jurisprudence, from Moore v. Gethaun to Salamaszynski and Wright highlight several important lessons. First, courts continue to emphasize that the expert witnesses owe a duty to the court, not the parties that hire them. Secondly, lawyers and experts can discuss their reports during the draft phase but the collaboration has limits. Last, if a party wants to demand production of an expert witness’ file, they must show improper conduct in the opposing party’s dealings with their expert.
Moving forward and as expert evidence continues to play a crucial role in litigation, the balance between legal guidance and expert autonomy will remain an essential focus for the courts in Ontario.
ABOUT THE AUTHOR
Casey Dorey is an associate lawyer at Bergeron Clifford LLP. He works primarily in Kingston but travels across Eastern Ontario.
Casey obtained his LL.B from the University of Leicester, United Kingdom, with First Class Honours. While in law school, Casey was a Moot Court champion and represented the school externally in London, England. He was also awarded the Canadian Spring Scholarship.
He has appeared before the Ontario Superior Court of Justice, Small Claims Court, Criminal Injuries Compensation Board, and the Social Security Tribunal.
