Since the offence of assault is quite broadly defined, that situation could definitely result in criminal assault charges. Of course, that would depend on the facts of the matter. It would have to be determined what had actually happened and whether the individual had simply tried to separate two quarrelling children. The decision to bring such charges would theoretically be left to the crown attorney. Authorities could also proceed differently in other cases, through disciplinary measures, for example. However, a teacher in that situation could definitely face criminal charges.
Now to answer your question, I can't tell you whether a teacher in that situation would necessarily be convicted if section 43 were repealed. As I told you, that would depend on different facts, and they vary from case to case. So I won't venture an opinion on that point.
However, as I said in my testimony before the committee on Monday, common law defences could also be used. De minimis and the defence of necessity are two defences that were mentioned in the Supreme Court judgment in Canadian Foundation for Children, Youth and the Law. There's also the defence of implied consent. Since these defences are available, I can't tell you with any certainty whether the teacher would be convicted in all cases in circumstances such as those you mentioned.
Section 43 would of course apply, but, as Judge Arbour held in the Supreme Court's judgment in Canadian Foundation for Children, Youth and the Law, the common law defences I just mentioned could be developed.