Originally Posted by The Guard
Batman didn't kill Ra's. Some of his actions may have led to Ra's Al Ghul's death, but this was more than partially due to Ra's own actions.
And at that point, Batman WASN'T trying to stop it, because he couldn't. He was using the surprise element of the tracks falling apart as a distraction to get the upper hand over Ra's.
Yes, he did kill him. He knew Ra's was in the train, and he made a premeditated action, by telling Gordon to blow the tracks. Knowing that he had the equipment to get out himself, and knowing full well that the tracks would be blown, he himself caused the very fate for Ra's. Maybe if Gordon blew the tracks on his own accord, without being consulted by Batman, maybe I could see it that way, but seeing as it was all Batman's idea, I can't see it any other way. He lead him into a trap he knew he wouldn't be able to get out of.
Just because he says the 'magic' words of "I'm not going to kill you, but I don't have to save you", doesn't deny the fact that it was a premeditated trap for Ra's.