There is a rather striking video currently used in police training. A firearms officer is caught on video shooting an armed suspect. The officer then gives his account of what happened, and there is no suggestion that he is tying to fabricate evidence. He says that he shot the suspect once; his partner says that he fired two shots. On the video we see four shots being deliberately fired. Memory, it seems, is an unreliable witness in situations of stress (which appears to be the point of using the video).