What is the test for functus officio?

This question, in my view, is one of mixed law and fact. While the interpretation of a contract or a statute is a question of law, it seems highly artificial to so characterize a tribunal’s assessment of its own manifest intent. A correct statement of the legal principle, on its own, would not resolve the parties’ dispute. Their dispute was “... about whether the facts satisfy the legal tests ...” relating to functus officio and involved “... applying the law to the facts... .”: Its resolution depends on the particular intent which this board had in these circumstances. This precise issue is unlikely to arise again and the result will be of virtually no precedential value. It is almost entirely a matter of “pure application”: Director of Investigation and Research v. Southam Inc., 1997 CanLII 385 (SCC), [1997] 1 S.C.R. 748 at paras. 35 and 44. These are the hallmarks of a mixed question of law and fact. [emphasis in original]