Surely everyone would be cool with it if a villain was killed in a fight. Like, some mobster is bringing it to Batman, and Batman is all like "KEEE-YA!" and kicks him in the groin or something and he dies. Dies of groin-kick. The worst way to go. That's just self defence on Batman's part. It's not as if we're necessarily talking about Batman lining them up and going at them with one of those big electric prod things they kill cows with.
