In Sattva Capital Corp v Creston Moly Corp, the Supreme Court of Canada established that contractual interpretation generally involves questions of mixed fact and law subject to a standard of palpable and overriding error, unless an extricable error of law is identified. The Court confirmed and specified this holding in a number of subsequent decisions. The new approach to appellate deference has sparked criticism from various parties in the legal community. A tension has emerged between the Supreme Court shifting away from the historical common law approach to deference and the appellate courts’ attempts to restore it. This article examines the theoretical foundations of this new case law development and proposes a methodological framework for distinguishing between questions of law and question of fact in contractual interpretation. The ultimate goal is to provide guidance on the choice of the appropriate standard of appellate review in this area. First, it is argued that the recent case law development introduced by the Supreme Court lacks rigorous analytical foundations and fails to provide adequate guidance on choosing the appropriate degree of deference on appeal. Second, it is contended that a useful methodological approach for distinguishing between questions of fact and questions of law is 1) to identify the cognitive task performed by the judge when adjudicating the contended issue, and 2) to assess the relative advantage of adjudicating actors in performing that cognitive task. Cognitive task refers to the type of judicial reasoning, or inferential activity, the judge performs when deciding an issue.