What's most disconcerting isn't simply that this happened, or that it was operator error (it was not the landing on the floor that caused the gun to go off but, rather, the "agent's" ineptitude with regard to picking it back up) - it's that the guy's knee-jerk reaction (emphasis on jerk) is that what immediately follows is a grin on his face and him walking in the opposite direction of the man he just knowingly shot in the leg.