During the scene where Snake is running on the roof of the World Trade Center, with the president, Brain, and Brain's girl, they jump into the same elevator Snake used when he landed there in the glider. After they enter the elevator, Brain throws something out just before the door starts to close. Now, when the door closes, look at the right side of the door; you can see someone's fingers/hand closing the door. This occurs at apr. 1hr 19min 50sec.