The law of expert opinion evidence has been in flux in recent years. A recent Ontario Divisional Court decision has provided some insight into an evolving option for parties to disputes: Dixie X-Ray Associates Ltd. v. Ontario (Minister of Health), 2025 ONSC 75 (CanLII).
The Court discusses the concept of expert evidence given by an employee of a party who has special expertise. The context was the interpretation of an OHIP billing fee Code. The decision of the Appeal Board resulted in a group of clinics being directed to repay the government over $1,000,000. A Medical Advisor for the Ministry of Health testified about the interpretation and application of the billing fee Code in issue. The Appeal Board accepted the admissibility of that opinion evidence. The Court held that this type of opinion evidence was permissible in this kind of circumstance, since the employee’s job was to interpret and apply the billing fee Code on a daily basis. The Court said:
After finding that the Medical Advisor met the criteria for a litigant’s employee with expertise, the Board … went on to consider, among other things, the extent to which medical records supported Dixie’s claim for facility fee J193 for a peripheral vessel assessment when an extremities ultrasound was performed. In the analysis, the Board considered the Medical Advisor’s evidence together with the evidence of Dixie’s radiology witnesses, ultimately reaching the conclusion … that Dixie had failed to establish that the Ministry’s Decisions were not in accordance with the [legislation].
To the extent that the Board’s analysis was focused on the interpretation and applicability of the facility fee codes and the medical records required to support use of those codes…, I have no particular issue with the Board’s analysis, apart from the question of procedural fairness.
The “litigant’s employee with expertise” witness is a distinct category of opinion evidence from the more common independent expert witness or a participant expert witness.
The Court also held that the Appeal Board had not simply accepted the expert opinion without analysis despite its closeness to the “ultimate issue”.
However, as noted, the Court found that the Appeal Board had been procedurally unfair in not notifying the parties that it was going to permit this relatively rare category of opinion evidence so as to allow submissions on the point or reply evidence and so a new hearing was ordered.
Regulators could theoretically see this type of opinion evidence proffered more frequently.