Continuity mistake: After a long car chase about mid-way through the film, the camera pans over the highway littered with smashed cars and hundreds of cars piled up. In the middle of this, you see a van painted a little like the Partridge Family bus....definately a one of a kind van. Then you see footage of the car which escaped the chase going down an empty side street and passes the same van. No way there are two vans like this one.
Continuity mistake: After Manny's fingers get crunched between the cars, blood sprays on his face. In the next couple of scenes there is hardly any there. Also, when the prison warden get sprayed with the fire extinquisher he is cleaned up in the following shots.
Continuity mistake: When Rambo fires the rocket launcher at the Russian Hind helicopter, he is clearly seen aiming a LAW rocket launcher. The LAW is fired by pressing a lever on the top. But when Rambo fires, a quick edit from a previous shot (on the patrol boat) shows him pulling a trigger from the Russian RPG launcher he used to dispatch the Vietnamese patrolboat earlier in the film. The film returns to show him holding the LAW rocket launcher again.
Plot hole: When Schaeffer, McFee, and Fergie drive to the Lapp farm to kill John, the car stops on top of a hill. Then it reverses a bit to be out of sight from the farm. But then the formerly careful guys get out and walk down the open road, sporting their guns like in an Italo western. (01:28:30)
Plot hole: When Diana turns up at her director friend's house she finds it crawling with cops as his girlfriend Christie has been murdered and the house is now a crime scene. She explains she lent Christie a coat and is there to pick it up - and a cop helpfully finds it on the floor and hands it to her. Are we to believe that a homicide policeman will hand over an artifact from a murder scene to an unidentified woman without making any attempt to confirm her identity, or even if the coat is even hers!? They don't even ask.
Revealing mistake: When Jesse is cleaning out his room, he puts a tape into his tape player, and presses a button down on the top of it. But halfway though the scene of him packing his things away, you can clearly see the button is no longer pressed down, yet the tape still plays. (00:18:10 - 00:19:00)
Continuity mistake: In the beginning, when the two shuttles have docked together, one of the NASA astronauts inserts some kind of key into the door and begins to turn it. When he does you hear a ratcheting sound, however, once the door begins to open and there's a shot from the inside of the uninhabited shuttle, the astronaut isn't holding any type of tool, and still the ratcheting sound can be heard as the door opens further.
Factual error: When Cressner falls and lands on the horn, it makes the same pronounced honk sound as when he had honked it at Norris. In reality this wouldn't be possible because the bell of the horn was compressed on landing when Cressner threw it out the window earlier, so the sound would've been higher pitched, if it was still able to make a noise at all.
Other mistake: Most of the obvious misses and awkward parts of the action in the opening can be attributed to the fact that it is revealed a few minutes later being just a drill. However, it does not make sense on any level. The training makes use of live explosives, and at the same time no gunshots are fired but only grenades, with unrealistic trajectories and range. The 'terrorists' don't use their rifles if not to try and bash the good guys on their skulls. That's quite the subpar training, but the top brass are impressed.