MAC gun glitch

On the "Return to Sender" part of Cairo Station there is a metal object moving back and forth. If you watch it lookes like when it moves back a bomb is loaded into it, then when it moves forward it drops the bomb into another hole. It is thought to be the mac gun ammo. Get in the way of the "metal object;" when it comes forward you will be dropped down the hole. You will die, but you get to see the room that master chief send the bomb out of when he opens the door in the cinematic.