“Under the Ontario Family Law Rules, three types of experts are contemplated: joint litigation experts, litigation experts, and participant experts. Only the latter two designations are relevant on this voir dire.
A “litigation expert” is defined in Rule 20.2 as “a person engaged for the purpose of litigation to provide expert opinion evidence.”
A “participant expert” means a person who is not engaged to provide expert opinion evidence for the purposes of litigation, but who provides expert opinion evidence based on the exercise of his or her skills, knowledge, training or experience while observing or participating in the events at issue.
Where a party seeks to call a litigation expert as a witness at trial, that party must serve an expert report at least 6 days before the settlement conference, which report must include an acknowledgement of expert’s duty (Form 20.2) signed by the expert. Other requirements include that the proposed expert must include in the report any instructions provided to him or her in relation to the case, and the expert’s reasons for his or her opinion. See the recent decision of Smith J. in Aldush v. Alani, 2021 ONSC 6410, setting out the applicable test and analysis in the case of a litigation expert.
By contrast, where a party seeks to call a “participant expert” as witness at trial, the acknowledgement of expert’s duty is not required, nor are the documents or information set out in Rule 20.2(2). The party must simply serve notice of the intent to call that proposed witness at least six days before the settlement conference, serve any written opinion of that proposed expert upon which the party intends to rely, and serve, at the other party’s request, a copy of any supporting opinion evidence the participant expert intends to provide.”
Children’s Aid Society of the Niagara Region, 2021 ONSC 8582 (CanLII) at 19-23
