How Many is Too Many: Limiting Defence Medical Assessments in D’Eon v Hosseini, 2022 ONSC 4397

How Many is Too Many: Limiting Defence Medical Assessments in D’Eon v Hosseini, 2022 ONSC 4397

Written By: Lindsay Charles and Sonam Sapra, Student-at-Law


D’Eon v Hosseini[1] arises from a motor vehicle collision that occurred on September 15, 2016, in which the Plaintiff sustained significant physical and cognitive impairments. As a result, the Plaintiff advanced a personal injury claim for damages, including loss of past and future income and past and future care costs. In preparation for trial, the Defendant sought to compel the Plaintiff to attend independent assessments with various experts that they had retained. However, the Plaintiff refused to consent to, or attend, the assessments.

The Parties’ Positions

The Plaintiff argued that assessments by the Defendant’s experts, including a neurologist, psychiatrist, physiatrist, and a vocational expert, would be unnecessary and premature. On the other hand, the Defendant submitted that the Plaintiff advanced a complex case involving issues of causation and damages. Thus, the Defendant argued that, to address these issues, it would be necessary to have several different experts assess the Plaintiff.

The Court’s Analysis

To begin its analysis, the Court noted that Rule 33 of the Rules of Civil Procedure provide Defendants with the ability to examine a Plaintiff with respect to a physical or mental condition that is at issue in the lawsuit. Further, assessments can be performed by a variety of experts, like occupational therapists and vocational experts.

The Court opined that while settled law dictates that a Defendant is not restricted to only one independent examination by an expert, this does not mean that a Defendant is entitled to multiple examinations by experts as a right. With respect to the number of experts a Defendant may have, the Court explained that there is no hard or fast rule. Rather, the number of experts that a Defendant is entitled to is informed by a number of factors, like the nature of the case, the type of injuries sustained and the evidence that has been garnered by the Plaintiff.

The Court emphasized that, when determining the number of experts that a Defendant is entitled to, a significant consideration is the issues that will be adjudicated at trial. Specifically, the Court noted that the law is clear that a Defendant is not entitled to an examination by an expert in an area which has not been placed at issue by a Plaintiff or to an examination by an expert whose expertise is duplicative or repetitive.

The Court also opined that, when a Plaintiff serves a report from a certain type of expert, it does not mean that the same type of expert must be retained by the Defendant. In cases where a Plaintiff has retained a specific type of expert, Defendants must consider various factors, like the availability of other evidence, to determine whether it is necessary to retain a similar type of expert.

Finally, the Court stated that when a party seeks to undertake examinations that are opposed by the adverse party, the onus is on the party seeking the assessments to demonstrate that the examinations are necessary for trial and that the assessments would not result in delays.

The Court’s Holding

To determine the necessity and reasonableness of the Defendant’s experts, the Court considered various factors, including the issues that would be adjudicated at trial. In doing so, the Court decided that the Plaintiff would need to attend assessments by the Defendant’s psychiatrist, neurologist and vocational specialist.


D’Eon v Hosseini stands for the principle that a Defendant cannot retain unnecessary experts to assess a Plaintiff. You do not have to automatically produce a Plaintiff for a defence assessment simply because you retained the same type of expert. Ultimately, when determining whether to produce a Plaintiff, it is important to consider whether the assessment is related to the issues that will be adjudicated at trial.

[1] 2022 ONSC 4397

Lindsay Charles


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