Continuity mistake: When Harrison Ford tries to enter the conference room when he comes upstairs from the lower level, he first struggles with the guard to the conference room door. While fumbling with the keys, the guard "wakes up" and shoots 2 shots toward Harrison Ford, where he turns around and shoots back. Those 2 shots from the guard leave bullet holes in the conference room door. When Harrison finally enters the room, the bullet holes disappear. When the bad guys return, the bullet holes are gone.
Continuity mistake: At the beginning, when AF1 is landed, and the two pilots and navigator get shot, a Russian guy takes over. AF1 is then driven around the airport. The Russian guy controlling AF1 speeds up to take off again. When he does take off he barely misses a plane that was on the ground. The next shot is from the back of AF1 and the plane that was on the ground has disappeared.
Continuity mistake: When Harrison Ford is fighting one of the terrorist guys, they go into a room with two chairs. Ford spins a chair to knock down the guy, and they keep fighting. As they go at it we see a knocked over stool with a black seat. Instantly, in the next shot, the stool is standing up, and in a perfect position for Ford to knock the guy out with. (00:44:30)
Continuity mistake: In the scene when the Russian is shooting the 3 doors, on the second door, if you look in slow motion, you see 2 muzzle flashes before a hole is made in the door. The same on the 3rd door. Also, when he shoots the 3rd door, he puts 5 bullet holes in it, but when he opens it to check, there are 6 holes in the wall.
Continuity mistake: When the traitor first begins to shoot the 3 people, we see a close up on one of the victims (the one who gets shot in the head). If you look behind him in slow mo, you'll notice that the furniture is already red (from the blood).
Continuity mistake: Defense secretary Walter Dean makes such a big deal out of getting the cabinet to declare the president to be incapacitated, he gets Attorney General Ward to draw up the papers. They are then given to the Vice President to sign, and there are 16 signatures on it, presumably all the members of the cabinet. Funny thing is, the names are pretty easy to read using the zoom feature on the DVD player, and not one of the names is Dean or Ward.
Continuity mistake: In the scene where the President is being escorted to the escape pod, there is an extra shot where the President is hiding on his own around the corner from a terrorist, who is sneaking around in the background looking for him. In both the preceding and following shots, the President is being physically escorted by two Secret Service men who are pulling him along and forcefully holding his head down. This shot is wrongly inserted into this portion of the scene and needs to be later in the film, when the President is trying to escape. (00:23:40)
Continuity mistake: In at least one external shot with the plane on the ground, the wing tips have winglets (angled-up extensions of the wing) of a Boeing 747-400. In other shots, the winglets are missing.
Continuity mistake: In the beginning when the hijackers are trying to take off at the airport there is a shot where the plane goes over some emergency vehicles (before it takes off). These vehicles disappear in the following shot when the plane hits the tree branches. Also, a taxiing jet would've blown the vehicles and people around. Nothing of the sort happens in that scene.manthabeat
Continuity mistake: When Agent Gibbs goes into the closed room and hands out the advance team reports from the Miami field agent, when he executes the three agents, if you watch, just after he kills the third agent, the agent's entire arm falls down behind the arm rest below the seat. However, in the following shots, when Gibbs re-holsters and turns to enter the armory, the agent's arm and hand are now risen upward, leaning against the window with his elbow propped up on the arm rest. (00:20:45)
Continuity mistake: When the President is finally discovered, they bring him upstairs. William H. Macy's hands are "taped behind his back" but notice when Ford finally overtakes Oldman, Macy's hands magically appear in front of him and he overpowers one of the guards. Finally he tells Ford to run after Oldman to stop the release, and his hand is taped behind his back again.
Trivia: A little aside - when the terrorists first strike, in amongst the confusion you can hear someone shout "get the football!" The "football" is the name used for the case which contains the nuclear launch codes, but this is never explained. It's not a major thing, but interesting to note that they included it as a little detail. Good to know a childhood spent reading Tom Clancy books wasn't wasted...