Factual error: The whole basis of the trial and conviction of Cameron Poe is a crock. The judge can not arbitrarily mete out a sentence that is harsher based on the ability of someone to defend him/herself. In justifying the harsher sentence because of Poe's military skills, the judge effectively says that Poe is more guilty than an average person due to his honorable and decorated service in uniform to his country. In my entire time in law school, I never read one out of the literally hundreds of cases I was assigned in which a judge issued a harsher sentence because of someone's innate or learned abilities to defend themselves. But since this was a movie court room proceeding, the fact that Poe had a witness to the fight (his wife), the fact that he was injured in the fight, and the fact that his uniform was torn and otherwise ruined as a result of the fight are never examined. A D.A. wouldn't have taken this to a grand jury on a bet, because they would have never returned an indictment or "true bill."
Revealing mistake: When Austin enters the bathroom at the casino, keep your eyes on the door during the scene - it opens by itself before closing. (00:31:10)
Revealing mistake: In one shot when the boat is pulling away from the waterfall, you can clearly see that the shot is the same one they used earlier in the movie. The water from the waterfall now is going up the cliff! They have just put it in reverse.
Factual error: The Russians stopped using steam locomotives in the 1970's. So bringing one out of retirement in 1997 to haul nuclear warheads would mean that your highly secret nuclear train would be well known among rail enthusiasts for weeks before.
Continuity mistake: Just before Demi Moore is about to get her head shaved she sees the base commander about equal treatment, and we notice very visibly that O'Neil has one side of her face bruised and all red and swollen. But in the next scene, which takes place moments later, when O'Neil is shaving her head, her injuries are all gone. Where did they all go to?
Audio problem: When Will Smith is looking at the two space ships at the MIB headquarters, if you look in the background Zed and K are there typing on the computer. But if you look closer you can tell that they're not even touching the keyboard and the sounds are just added into the movie. (01:16:00)
Plot hole: In the final showdown, when Bond is fighting with Stamper, the girl is wrapped in a chain, hanging from a crane and dropped into the sea. After the boat blows to bits, the chain continues to hang down, even though there's nothing holding it. It even keeps hanging after Bond's swum down to untie her. What's keeping it there? Do all stealth battleships come with buoyant chains? With both arms at least partially free, why doesn't she just climb back up the chain?
Continuity mistake: In the beginning of the movie, when the little girl is falling, they film her falling all the way down backwards. When they flash to the young Simon's face and the priest and back to the girl she lands face down.
Continuity mistake: The whole big prison bus escape scene revolves around Chris Tucker being handcuffed to the French guy, but when Frenchy's friend arrives in the bus he stands up and hugs him while the handcuff is shown completely unlocked from Tucker's hand. In the next shot and the entire next scene they are still handcuffed together.
Factual error: Just before Declan and the Jackal start shooting at each other in the subway tunnel, one of the trains starts coming from the opposite direction and begins passing Declan. This train continues to pass him at full speed for a full 35-40 seconds while they shoot it out. Subway trains are not nearly long enough for that. Also, during this time another train comes from behind him and he has to get between them and hold onto the light for a few seconds while they pass. But the second train then passes first while the first one passes fully about 2 seconds after the second one came... and it got there first, by about 15-20 seconds. Subway lines are about the same length as each other as well. But the first one was way longer and way wrong. (01:49:30 - 01:50:05)
Visible crew/equipment: In the shoot 'em up scene at the hangar near the beginning of the film, right after Tito and Wanda take down Pollux, when Troy shoots an agent in the stomach and the agent flies back - you can see at least two cable wires pulling him backwards. You can first notice the 2 wires when the agent is running in slow motion right before he shoots him. (00:14:15)
Continuity mistake: Toward the end, Carmen Ibanez gets stabbed through the shoulder when she is brought before the big master alien thing. If you were to sustain such an injury, there would be so much swelling, not to mention just destroyed tissue, that you wouldn't be able to move that arm for weeks. Yet a few minutes later, she is seen hefting around a very large assault rifle, and seems to have no difficulty. I guess it's a pretty standard action movie "heroes can temporarily ignore injury in order to save the day" kind of oversight, but it just seems exaggerated in this case, considering how severe the shoulder trauma looked. (01:48:15 - 01:53:40)
Continuity mistake: In the scene where Lyle and Ursula slide through the river then over the falls, when they go over the waterfall they are both dry.
Continuity mistake: In the scene where the town folk are having an outdoor festival, Steven Seagal is invited to play with the band. An older gentleman hands him a guitar with nylon string tuners (open headed classical type) but when he takes it from him, it is a Steel string Martin Acoustic (solid headed flat top) guitar.