Factual error: The payphone McClane uses in Dulles airport has the "Pacific Bell" logo. Pacific Bell is a West Coast phone company. (00:04:20)
Continuity mistake: When Richard Thornburg is in the aeroplane bathroom giving his live report, in a number of the shots he is holding the phone upside down. (01:37:00)
Continuity mistake: Bruce Willis is emerging from an underground air-vent when the plane with General Esperanza is landing. Initially the plane is coming on a direct course for him and he struggles to get out. In fact the front wheel is on course with and knocks the vent cover. But in the very next scene, the tire marks clearly show the front wheel passed to the right of the vent and so completely missed it. (01:11:40)
Revealing mistake: In the skywalk scene, when McClane pushes the paint stand on the terrorist, it is quite obvious that they use a dummy when the paint stand falls on the terrorist and crushes him. (00:45:05)
Revealing mistake: Obvious stunt double for the black terrorist during the fight with McClane in the baggage area. He looks younger than him and has a different hairstyle. (00:14:10)
Continuity mistake: When Col. Stuart is talking to Gen. Esperanza on the walkie-talkie about what runway to land on, behind Stuart you can see one of his men walk up to the map of the runways. Stuart turns around and starts walking to the map and the guy isn't there anymore. When Stuart gets in front of the map, the guy comes up and tells him which runway Esperanza should land on. (01:09:05)
Continuity mistake: When McClane is desperately trying to get out of the manhole cover to avoid the plane, he props it open with a steel bar. Moments later, just before the plane runs over it, the bar is gone, so there should be nothing holding it open. The size of the gap between cover and runway also decreases between these shots. (01:14:50)
Revealing mistake: On one of the first shots of inside Holly's plane, you can see the blue screens through the windows. No, it's not blue sky, in all the following shots the sky outside is orange. (00:16:30)
Continuity mistake: The dead bodies of the SWAT team move around on the escalator between shots. The best example of this is after the last SWAT guy dies, there is a body or two near the end of the escalator. They disappear or at least move much further away after McClane drops his gun on the escalator. And all this happens while the escalator is not moving. (00:45:15 - 00:48:00)
Revealing mistake: Throughout the whole movie, bits of 'snow' stuck to various things in close up view (i.e. guns, hair, faces, clothing). Look closely at the snow, its quite obvious that they are actually little thin scraps of white plastic. Most evident is in McClane's hair when the platoon is about to move in on the church, the shot of him saying "You're not such an asshole, after all." (01:27:55)
Continuity mistake: John McClane and Major Grant are fighting on the wing of the aeroplane, and Major Grant's mouth gets extremely bloody. The shot switches to McClane and then back to Grant, whose mouth is still bloody. However, after the shot switches back from McClane to Grant, Grant's mouth is no longer bloody. (01:47:10)
Continuity mistake: When John is coming out of the drain on the runway, in shots facing him it's snowing, and in the shots that face both John and the plane, it's snowing. Yet, when the camera is just on the plane it's not snowing. (01:13:30)
Continuity mistake: Two guys dressed in red go to the church and are let in by the old man. One of the men then says something like "You were right about that," and the scene shows him shoot his gun with his arm outstretched (obviously). The next scene though of the old man falling backwards shows the shooter's arm down by his side, however in the next scene where it cuts back to the shooter his arm is outstretched with the gun again. (00:07:30)
Other mistake: When the platform falls on top of McClane and he drops his gun, I don't see how it would land more than six feet away from him. One foot at the most. Unless of course it was made of rubber. (00:47:05)
Visible crew/equipment: When we first go to the Annex Skywalk, the SWAT team are walking with the guy from the tower and he is talking on a radio. In the mirror behind them you can see the boom mike and operator as they walk.
Revealing mistake: McClane jumps out of the helicopter at the end and lands on the wing of the larger airplane. The stunt man who does this then proceeds to move up to a long wire on the side of the wing. Any normal airplane would not have a long wire on the wing.
Continuity mistake: When John and his wife hug, his hand suddenly appears on her head.
Answer: Because the police were moments away from arriving at the scene. They needed as much time to get away without being tracked. Every moment counts. And a target rocking about a few hundred feet in the air doesn't seem to be such an "easy target".
XIII