This was an Application by the Plaintiffs for an interlocutory Injunction prohibiting the Defendant province from denying Injectable Opioid Agonist Treatment (“iOAT”) until the final determination of the underlying Action. The underlying Action concerned the constitutional validity of the Defendant’s decision to change the way that it provides iOAT to patients.

Among other things, the Application involved expert witness evidence from a multitude of individuals. Expert witnesses were called upon by the Plaintiffs to explain the effects and elements of opioid use disorder and its treatment, and to predict the likely impact of proposed changes to the Defendant’s existing program. The Court noted that introduction of expert evidence is permitted on Applications, pursuant to Rule 6.11, and should be introduced following the same procedure as at Trial.

In advance of the hearing, the Court advised the parties that it would be seeking submissions respecting Rule 8.16, which states that, unless the Court otherwise permits, no more than one expert may give opinion evidence on any one subject on behalf of a party. The Plaintiffs argued, based on the Rule’s location under Part 8 of the Rules, that Rule 8.16 applies only to Trials, and not Applications. The Court agreed; however, it went on to find that the same concerns regarding necessity and limitation of expert evidence continue to apply. Accordingly, it held that where a party wishes to adduce evidence from multiple expert witnesses on a given subject in a Chambers Application, such party must seek leave in advance.

The Court noted that leave had not been sought in this case. However, since failure to obtain leave had not been specifically raised by the Defendant, the Court chose to evaluate permissibility on the basis of relevance, necessity and proper qualifications. Though some witnesses were ultimately rejected, and others accepted, the Court came to the conclusion that an interlocutory Injunction could not be sustained in the circumstances.