You can make this funny thing happen on any level with Imperial's. Then do not move him at all. Soon he (although he is dead) will start shooting you! This is another funny thing. You can make this funny thing happen on any level with Imperial's. After killing an Imperial man, quickly force grip him before he disapears. Then move him over to the top of a door, and you will notice he grips it and won't let go. You can attempt to move him, but it won't work.