Continuity mistake: The green Alfa in the opening minutes has its side, and mirror, wiped out by a lorry. For the next 5 minutes it then drives around in perfect condition. (00:05:43)
Factual error: The vents that Hunt and his sidekick crawl down at CIA Headquarters are standard galvanized steel box vents; they are very common in the building trade. Try walking or crawling down one - you'll make a noise like the sky is falling down. People will be able to hear you for miles. Every person in that building would know somebody crawling about in the vent system. (This error applies to dozens of films, not only this one).
Factual error: The radar guided SAMs are consistently evaded/triggered by the pilots' flares, which in reality only work against heat seeking missiles. Radar guided missiles would be defended against using chaff, basically clouds of aluminium foil strips. It was mentioned in some interviews they didn't want use chaff as it wouldn't really be visible for the audience - hence why they only deploy flares.
Continuity mistake: When Pierce's wife is walking in her auto shop they pan down to show her red Louboutin heels, then they cut to her walking in her office, and when they show her shoes again they have a tan sole.
Other mistake: When the stormtroopers break into the control room, the stormtrooper on the right of the screen hits his head on the door frame. On the DVD release they've added a thump when he hits it. (01:18:55)
Continuity mistake: When Sam is in his bedroom, after he finds the Cube sliver it falls and dramatically burns a hole through the floor into the kitchen. But Sam's bedroom is over the living room (there is nothing on the ground floor below Sam's elevated bathroom, and in the first movie Jazz hides in this open space), and the kitchen is actually located between the den and dining room, at the other end of the house. If they were to follow the actual floor plan of the house, the Cube sliver would have landed in the area of the piano in the living room, but where would the fun have been in that? (00:12:30)
Other mistake: Murphy lands the helicopter on a railway line so an oncoming train will destroy it completely, and this happens exactly on cue with huge, dramatic explosions and flying debris. Apparently the train driver doesn't think this is important enough to interrupt his busy schedule - he doesn't stop the train. We do not hear brakes being applied - the wheels would make a noise like the sky coming down - and the train doesn't slow down at all - it just keeps on going.
Factual error: Near the end of the film Knox is flying a Huey helicopter and the Angels hitch a ride by shooting it with a spear gun and dangling on the line behind it. Suddenly adding about 200kgs to a Huey in flight like that is going to cause all sorts of problems with the trim and airspeed of the aircraft - the pilot would know immediately that something was wrong. (01:23:20)
Factual error: The movie starts in 1985, jumps '5 years later' and then back to Sasha Luss, then '3 years earlier'. So, in her crusty apartment in an impoverished neighbourhood of 1987 Soviet Russia, Anna is filling a form on her notebook-style laptop, too modern for the era. It looks like a NEC UltraLite (considered the first notebook style laptop) which didn't even come out until 1989, let alone the likelihood of someone in the USSR having one.
Visible crew/equipment: In the "Battle of Carthage" in the Colosseum, one of the chariots is turned over. Once the dust settles you can see a gas cylinder in the back of the chariot. (01:22:55)
Factual error: Why is Hilts not wearing a uniform? A serving officer captured behind enemy lines in civilian clothing risked being shot as a spy. If a prisoner's uniform was too worn or damaged to wear, it was routine for the German authorities to replace it - a P.O.W. in civilian clothes is an obvious escape risk. He is wearing a pair of tan chinos, a cut off sloppy Joe sweatshirt, both ridiculously anachronistic - Sixties hipster fashions - and nowhere even close to a World War 2 uniform. He is also wearing Army Type III Service boots - something that would never have been issued to a fighter pilot.
Continuity mistake: In the final fight scene on the plane between Jinx and Agent Frost, Jinx is slashed across her stomach, drawing blood. In a later scene, when Jinx and 007 are pouring diamonds over one another in the hut on the cliff, her stomach is unblemished. (02:02:25)
Continuity mistake: After chasing down Sully, the yellow Porsche is totally wrecked on the left side, until Arnie drives it away, and it's fine. Later, when Arnie and Cindy arrive at the hotel, the car is wrecked again. (00:39:50)
Visible crew/equipment: When Tom and Sonic pull over and the mini drone explodes, knocking Sonic unconscious, the camera pans away and you can see emergency vehicles blocking the road on the right of the screen, presumably closing down the road for filming. (00:59:55)
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."
Factual error: When Ray leaves his wife Gina and his car is hit by the truck he should still be in England, but when he is being chased through the streets he is in South Africa, the cops in the car are not in English police uniforms or vehicle, police livery is incorrect, and all vehicles have South Africa plates, not English number plates.
Other mistake: Throughout the film Mason goes through all sorts of shenanigans - explosions, fire fights, falling off a cliff, almost drowning, this woman really goes through the wringer. It's a bit surprising then, that at the very end of the film when the good guys finally come to the rescue that she looks like she has just finished posing for a shampoo commercial with not a hair out of place.
Factual error: In circling over Washington Dulles, a plane would fly over several airports that they could land at with perfect communication, including Richmond, Baltimore, Andrews AFB, etc. Also, there is no communication from the airport to the plane but the plane would be in range of no fewer than 15 transmitting stations that could have relayed messages.
Factual error: Amongst the essential parts of a nuclear weapon's detonation mechanism is a radioactive isotope of tritium, which has a half life of just 12 1/2 years. The tritium in every nuke on earth has to be replaced every ten years or so. This is by no means unusual; there are other perishable parts including detonators made of conventional explosives which would be completely inert after a thousand years. After lying dormant with no maintenance at all for that amount of time the nuclear weapons the 'Man-animals' find would be big shiny paperweights and not much else.
Visible crew/equipment: When Melissa dodges the truck that has fallen from sky and Dusty rushes to open a door and help Melissa get out of the truck, the reflection of a camera is seen in the bottom right corner of the truck window. As they move out and pan to the right, you can see a reflection of the same camera and cameraman at the bottom right corner of the truck door as they move away. (00:33:50)
Suggested correction: Knox wasn't a trained pilot. Either he had no clue to what was going on, or he thought something may have been wrong, but didn't know what to do about it.
Taking off and landing a helicopter are by far the most intense and difficult part of a pilot's training. Seriously, 99% of learning to fly is learning how to land and take off. If the pilot is skilled enough to take off in a Huey he is easily skilled enough to notice a massive additional drag on his helicopter due to the additional weight of the angels and the air resistance put up by such a bulky protrusion on his aircraft. If he isn't skilled enough to notice that, he isn't skilled enough to take off in the first place.