Revealing mistake: During the attack of the Global Sedition on the space station at the beginning of the film, several objects can be seen with dark grey boxes around them - CGI artifacts. One clear time is when Ranger 1 is saying "Damn, can't shake him". (00:02:35)
Visible crew/equipment: In the very first scene, the boom mic is very obvious at the top of the screen.
Continuity mistake: In the scene where they are talking to Snipes girlfriend. Downey says he killed them with his bare hands and shows her a picture of a guy shot twice in the chest.
Visible crew/equipment: When Alan throws his father's broken radio into the box and he turns around to talk to the girl on the ladder, the reflection of a crew member wearing a white T-shirt can be seen in the monitor on the desk as the camera follows Alan. (00:30:40)
Factual error: When Christian Slater and Minnie Driver are trying to get out of the water before it reaches the transformer, there is a real big problem with this scene. If there really was a flood and it was rising that high, the city should have shut off the electricity to the entire city, to prevent any electric hazards that may happen in that situation.
Continuity mistake: When Vivo finds Pantucci snooping around the cargo, he throws him to the middle of the mercenaries, and they all get around him, including T. Ray who smiles at him; when T. Ray smiles at Joey he is standing up, but when he gives the first kick he is sitting down.
Continuity mistake: In the beginning, as Nielsen plays his violin you can see a quiver on his back, the next scene it is gone.
Continuity mistake: In the tanker, the girl and the CIA guy are bound to the chairs. When the tanker is jolted and every person gets pushed away, the girl's hands come loose, as her chair is thrown. Yet in the next shot both her hands are tied again.
Continuity mistake: While the hitmen are kidnapping Nishi's daughter, we see her and her boyfriend in the back of the limo. As the boyfriend is trying to undress her we see that she is wearing ordinary white knickers. Then when Mark Wahlberg lets her use the bathroom, we see him pull her knickers up for her (she is handcuffed), which are now more like hotpants.
Plot hole: Alain joins the Legion, goes through extensive training and eventually gets his photograph taken. That's how Galgani recognises him and sends two men to kill him. They arrive with a platoon at the fort just after Alain, Mackintosh and Luther. The photograph would have taken a while to get back to France and then the two men would have to go through the same training. So how do they both end up in the same fortress after they joined the legion long after Alain?
Revealing mistake: Just after they dump the tacks out of the window, the Russians' car flies up into the air in a really quite impressive car crash. Just before it flips over though, you can see the huge ramp put in front of it. (00:32:20)
Continuity mistake: In the love scene between Mario Van Peebles and Rae Dawn Chong, her breast is uncovered, then covered, and then uncovered again.
Continuity mistake: In a bar scene when Doplh Lundgren is doing shots, he does one, the camera pulls out and he finishes the already completed shot.
Visible crew/equipment: A boom mic drops in when the hitwoman is asking where Riley is, after the shootout.
Continuity mistake: When John and Meg are trying to escape the carwash in the car, in some shots the back window of the car is totally missing and in others there is a large section of shattered glass still there. (00:41:24)
Visible crew/equipment: Just after Tarzan goes under the stone door, he finds the torches dropped by the bad guys. The flame from one of the torches is reflected in the camera lens, and was caught on tape. It looks like a single, unattached flame is hovering on the stone wall nearby. This is made even better when Tarzan picks up the torch and then drops it, the reflection follows his movements precisely.
Factual error: After we are shown an aerial shot of New Orleans, then we see the scene where Lawson Russell pulls up in a New Orleans cab outside of a skyscraper. The only problem is, the skyscraper is the Library Tower, which is situated in downtown Los Angeles. (00:38:00)
Continuity mistake: In the movie, notice how the red sport utility vehicle driven by Bill Paxton goes from shiny and clean to very dirty and dusty, from one shot to the next, all within the same scene.
Continuity mistake: During the final fight between Cain and Todd, Todd breaks Cain's arm at the elbow and wrist. In the next shot Cain is staggering backwards as Todd winds up for another blow. You can clearly see that Cain's arm is fine and resting comfortably at his side. (01:24:13)
Revealing mistake: When Suzi Amis is hanging from Howie Long's leg in the parachute scene, you can see that the stuntman is not holding on to his leg, but some kind of wire harness.