In The Khallos Express story mission, when you climb up a ladder to the first train car that you can fall off, kill the Elite Henchwoman. Then, stand in front of Harry Tipper where the Elite Henchwoman died so that he cannot run further. Back up slightly and he will start running. Shoot him immediately and start to move yourself so he is between you and the edge of the train car. He will start to stumble towards the edge until he falls off. Just before he hits the ground and dies, he will disappear. Throughout the level you will still hear him talking as if he were next to you. This glitch may require a few attempts, as the game may declare game over if you fail to knock him off the train.