It all depends on what the technique/move does, it may simply be that the technique/move is a hax that ignores durability, or that character B's durability does not scale to his AP, or that character A has simply taken advantage of some weakness of character B (an example would be someone small being able to easily defeat someone much larger, muscular, etc. with just martial techniques and that would not scale martial techniques to AP), he would not necessarily scale AP with the technique unless the technique makes it clearly explicit.