Perhaps you can put a chain over his nose? Give it a couple of quick jerks before you lead him out of there, and that will get his attention. Does he explode out of the gate only when it's time to eat, or all the time?
He's not sound so I don't mess with him at all. He only comes up at feeding time. You know, I've had him for 7-8 years or so and this just started.
All the suggestions are excellent. I'm going to use all of them! Different day, different tactic, keep him guessing.