Did anyone notice how bad the editing was in the film.
The bomb seems to have eleven minutes and something for a long time. From about the time Talia finishes her flashback speech, all the way To Batman boards and takes off in his stupid jet bat thing. It's still in eleven minutes. Two minutes later we're at five minutes something. And with a minute and a half left Bats has time to secure a grapple to the device (which always takes longer than a second) talk to Catwoman, give her a kiss, tell Gordon who he is, and then fly off. Wow.