The Ontario Court of Appeal in Mardonet v. BPO Canada LLP determined that a motions judge’s order quashing a summons to a party is interlocutory, even if the summons is issued for a motion in which the party is not involved.
In Mardonet, the plaintiff sued the appellants to recover funds that were allegedly misappropriated and alleged that the moving parties were negligent in conducting audits and failing to detect the misappropriation of funds. The plaintiff moved for a Mareva injunction against the appellants, who in turn served notices of examination against the moving parties. The notices of examination were quashed by a motions judge.
While the moving parties submitted that the order under appeal was interlocutory, the appellants submitted it was final. Relying on Smerchanski v. Lewis, which held that an order quashing a summons to a non-party was final because it finally disposed of the rights of both the non-party and the party who issued the summons, the appellants submitted that the moving parties were the effective equivalent of non-parties.
The Court of Appeal disagreed with the appellants, finding that since the moving parties are parties to the action the order is interlocutory:
 We conclude that the order under appeal is interlocutory and that the appeal must be quashed. The key factor in this court’s decision in Smerchanski was that the summons was issued to a non-party. That is not this case. The moving parties are parties to the action. The reasoning in Smerchanski does not apply. The order under appeal does not finally determine whether the moving parties can be examined in the action.
 Further, the fact that the motion judge’s decision may finally determine whether the moving parties can be examined in relation to the Mareva injunction does not make the motion judge’s order final. The motion judge’s order does not terminate the underlying action or resolve a substantive claim or defence of one of the parties. To hold that the motion judge’s order is final because it determines whether parties to an action can be examined in relation to an interlocutory motion would effectively eliminate the distinction between interlocutory and final orders: see Waldman v. Thomson Reuters Canada Limited, 2015 ONCA 53 (CanLII),  O.J. 395, at para 22.