The British Columbia Court of Appeal in Cambie Surgeries Corporation v. British Columbia (Attorney General), 2017 BCCA 287 and the British Columbia Supreme Court in Ewart v. Nippon Yusen Kabushiki Kaisha, 2017 BCSC 1442 recently addressed whether rulings in the course of a trial or motion can be appealed prior to the conclusion of the hearing. They cannot. Such rulings are not appealable on a free-standing basis either with leave or as of right.
In Cambie Surgeries the plaintiffs sought to appeal three decisions made in the course of a trial concerning expert evidence on the basis that each one gave rise to a limited appeal order.
As the decisions the plaintiffs sought to appeal from were made during the course of a trial and concerned evidentiary matters they are referred to as "rulings," as opposed to a "judgment" or "order." The issue was whether the Court of Appeal has jurisdiction to entertain appeals from evidentiary rulings.
The Court of Appeal held it does not have jurisdiction to hear free-standing appeals from evidentiary and other rulings made during the course of a trial. The fact that the rulings were formally documented does not make them appealable: "what governs is substance, not form" (para. 39).
The "modern genesis" for this principle is Rahmatian v. HFH Video Biz, Inc. (1991), 55 B.C.L.R. (2d) 270 (C.A., Chambers), where Chief Justice McEachern held a dismissal of a no-evidence motion was not an order but rather, "a ruling, or a ruling on evidence which is part of the trial process, and is not appealable until after the trial has been completed" (see: Rahmatian at 272).
Treating an evidentiary ruling made during a trial as an appealable order would be inconsistent with the long-accepted principle that it is always open to a trial judge to revisit such rulings (see: R. v. Adams,  4 S.C.R. 707 at paras. 2930; R. v. Cole, 2012 SCC 53 at para. 100; Rule 12-5(2)).
Following Cambie Surgeries, a similar issue arose at the trial level in Ewart in the context of a certification motion.
In Ewart, the defendants sought to adjourn a certification motion on the basis they were pursuing an appeal of a dismissal of an application to file a further affidavit of an expert, with reasons to be included in the ultimate certification ruling. The defendants argued the hearing of the certification motion should be adjourned pending the determination of that appeal because, in the absence of an adjournment, there would be a "real prospect of prejudice to the Defendants as well as substantial inefficiencies for the parties and the Court" if the appeal were allowed and the motion would have to be re-argued on a different record.
The chambers judge held evidentiary rulings during or leading up to a hearing are not "orders" and therefore not subject to appeal, referring to Cambie Surgeries. Recognizing Cambie Surgeries dealt with rulings made during a trial, the chambers judge concluded there is no meaningful distinction between that context and evidentiary rulings made in a certification motion, stating: "the same factors that the Court of Appeal alluded to in Cambie Surgeries apply here: it is not efficient to down tools in the middle of a proceeding to allow appeals on evidentiary rulings" (see: para. 4).
Formal orders should not be entered in respect of evidentiary rulings made at trial, and "counsel should refrain from submitting such orders for entry and judges should decline to sign them" (see: Cambie Surgeries at para. 66).
In the event a ruling has an impact on the disposition of an action or motion, it is subsumed within the order and can be raised as a ground of appeal on an appeal taken from the order entered at the conclusion of the trial or motion.