Yeah, there was nothing Joker-like about how Jason Todd died; beaten with a crowbar and blown up is far too mundane for Joker's tastes. If Joker's going to kill a major character it should be done in a way that makes the reader laugh, then feel horrified that they're laughing at something so sick and depraved, then laugh some more.
That's not to mention that the very concept of the Joker being scared at all is pretty OOC, and he's never been the least bit scared of Batman.