When a motion judge exercises her new fact-finding powers under Rule 20.04(2.04) of the new summary judgment rule, is this a case of mixed fact and law?

In my view, absent an error of law, the exercise of powers under the new summary judgment rule attracts deference. When the motion judge exercises her new fact‑finding powers under Rule 20.04(2.1) and determines whether there is a genuine issue requiring a trial, this is a question of mixed fact and law. Where there is no extricable error in principle, findings of mixed fact and law should not be overturned absent palpable and overriding error: Housen v. Nikolaisen, 2002 SCC 33, [2002] 2 S.C.R. 235, at para. 36.