Even in the comics not every itteration of Batman has had the no kill policy. Heck even the Nolan Batman that DID have it killed in all three movies, albeit in justifiable circumstances. Anyone who didn't make it out of the flaming monastery, Ras at the end. "I'm just not going to save you" doesn't count if you masterminded the crash in the first place Batman. Harvey Dent. Talia al Ghul.