Admissibility of Expert Evidence

A person with a magnifying glass looking at papers


There has always been concern about potential conflicts in how experts are instructed and managed by counsel, and in particular, how draft reports and other of the expert’s work product should be managed in order for an expert’s report to be submitted as evidence in Canadian civil trials.

This issue came to a head in 2014, in Moore v. Getahun, where a Court ruled that communication and instruction should be quite limited. The ruling that struck fear in the hearts of many litigators, as it was contrary to what had evolved as common practice among many.

Appellate court rulings in 2015 provided much-needed clarification on the issue (and unwound much of what was ruled in Moore v. Getahun). One important decision restored the validity of traditional pre-trial communications between litigants and their expert witnesses; a second one offered new guidance on when allegations of bias are sufficient to exclude expert evidence; and a third reinforced the discretion of trial judges over what expert evidence is admissible.

Lexpert’s US/Canada Cross-Border Guide–Litigation, “Admissibility of Expert Evidence“examined the matter. Jeff Pellarin was pleased to have contributed:

Jeff Pellarin, President of Pellarin Inc., a Toronto-based forensic accountant and business evaluator who is frequently called as an expert witness, says “there is some molding of the expert opinion that occurs while the mandate unrolls; that happens, say, 50 per cent of the time.” For example, he says, the plaintiff may have a choice of two remedies to seek. “Sometimes counsel may ask you to start calculating the amount of each remedy, and when it becomes clear which yields the higher number, they’ll tell you to just do a report on that remedy, because they’re not going to pursue the other one.”

This reinforces our long-held view that, while independence of experts is paramount, some interaction can aid in the litigation process, making it ultimately more efficient and timely for all parties.