Near the end of the movie, when Neo is shot by Agent Smith the first time, there is a bloody splotch on the wall of the hallway behind him. However, Neo does not get pushed up against the wall until he is shot the second time. It doesn't show the blood splotch again until Neo slides down the wall to the floor. This time, the blood is streaked down the wall where he slid. Apparently, they didn't clean the blood splotch off the wall between the last take and the one they used in the movie.