Come to think of it, why the hell did he put Commissioner Gordon in the Batmobile and task him with making the critical train-destroying shot? Gordon has never even seen that kind of sophisticated technology before, and he even misses his first shot. What if he hadn't managed to blow up the tracks in time? What if he'd pressed the eject button by accident?
"I played Space Invaders back in '79. I got this."
Batman should've shot out the tracks himself. Even if by some miracle Liam Neeson managed to stop the speeding train in time, his plan is totally screwed. It's not like he could toss the microwave cannon on his back and run the rest of the way, and if he tried, Batman would already be sitting there with his Batmobile cannon pointing at the train. The "World's Greatest Detective" added two completely unnecessary and needlessly risky steps to his supervillain-thwarting plan.