What is the standard of review for mixed questions of law and fact?

It is trite law that questions of law are to be reviewed under the standard of correctness and that questions of fact are to be reviewed under the palpable and overriding error standard. As to mixed questions of fact and law, they are also subject to the palpable and overriding error standard unless there is an extricable question of law. In such a case, the correctness standard will apply to the question of law (Housen v. Nikolaisen, 2002 SCC 33, [2002] 2 S.C.R. 235 at paragraphs 8, 10 and 37) [Housen].