What is the difference between an interlocutory result stemming from a failed “no reasonable cause of action” motion and a final result from a determination of a question of law?

The difference between an interlocutory result stemming from a failed “no reasonable cause of action” motion and a final result from a failed “determination of a question of law” motion was made clear by Morden J.A. in the R.S. case at para. 18: In my view Ball v. Donais is distinguishable from the present case. Both the terms of rule 21.01(1)(a), under which the order had been made, and the terms of the order itself, which were in accord with the purpose of rule 21.01(1)(a), indicate that the order was a final one. The order finally determined, subject to appeal, that the defendant's limitation period defence was not open to him. In the case before us, although Benotto J. gave very clear reasons for her conclusion that the defendant had not met the burden of establishing that the plaintiff did not have a cause of action, she did not finally resolve the question. As I have said, the purpose of rule 21.01(1)(b) is to enable claims and defences that do not, in law, have a chance of succeeding, to be stricken from the pleadings.