It might actually be an involuntary muscle spasm caused by god knows what that causes some dogs to set their jaws impossibly hard and continue while the dog is dead. be logical LOCK JAW. LOL
Or maybe it's because you know, "pit bulls'" brains grow too big for their skull and one day the just "turn" and lose their dang minds and just start mauling people?
See how that sounds?
I already made my point. All in all, moral of the story is, bulldogs have powerful jaws, yes, and the good ones stay in hold. But they sure don't have lock jaw, lmao.