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.
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.
Other mistake: When Adam comes in and says "when I woke up this morning, the pain was gone", Connie is mouthing his lines behind him.
Other mistake: In the slaughterhouse scene, after Harrigan has injured the Predator with his shotgun and Keyes reappears, the Predator throws its disc, and severs Keyes in half at the waist. We see his legs flop to the ground, and blood pour from above, but his upper half (torso, backpack and weaponry) mysteriously remain hovering out of sight. (According to the director, the MPAA made him cut the footage of the top half of his body hitting the ground because it was too gory, creating this odd error). (01:21:50)
Other mistake: Fireworks use heated metals to produce the various colors seen when they explode - Iron, Nickel, Cryolite, magnesium and copper filings. Flying a jet engine through exploding fireworks would cause serious damage to the engine.
Other mistake: The female journalist is called Samantha Coleman through the movie, but appears in the credits as Samantha Copeland.
Other mistake: When Sam and Frodo are in the field with the scarecrow, you can plainly see a car cruising past in the distance, from right to left. Further comment - there are two different shots which show the car moving from right to left. One starts at the top right distance, and in a shot a few seconds later the car has traveled down the road a bit and is more easily visible. Complicating matters is that the dust thrown up by the car looks similar to smoke from a chimney in the right distance, making some people think it is just the chimney. But chimneys don't move, and the smoke from the chimney is separate from the moving vehicle. [It is deleted on the DVD, but you can still see an obvious bit of image fakery on the hill just left of the smoking chimney. One can see the hill, tree, and surrounding area move up and down and shimmer slightly where someone has done a cut and paste to cover up the auto. The "car inclusive" scene appears on the National Geographic documentary, "Beyond the Movie The Lord of the Rings: The Fellowship of the Ring." Also, watch the music documentary on the Extended DVD - when it shows this scene the car is still in it. Bizarrely, in his commentary Peter Jackson said he never saw a car and doesn't know what people are talking about, but the production/post-production team say in their commentary that despite not thinking anyone would be able to see it, they took it out anyway.] (00:42:55)
Other mistake: At the end of the film when they arrive in NYC looking for the library, we know that they survived because they are inside with a roaring fire burning. But where is the smoke up above, as Jack Hall approaches? There must be a chimney, or else they would have all died of asphyxiation.
Other mistake: When Rick and Ardeth Bay save Evie from the warehouse after Imhotep is resurrected, there are four mummies chasing them when they get on the double-decker bus. Rick shoots one of the mummies and "kills" it. He shoots another one in half and goes to the top of the bus to fight another one. The top portion of the mummy that got shot in half then fights Ardeth Bay. Evie kills the mummy that got shot in half and the top part of the bus gets torn off by the bridge and kills the mummy Rick is fighting. John stops the bus and they all sign with relief. Whatever happened to the fourth mummy chasing them? (00:43:20 - 00:46:40)
Other mistake: The scene at Columbia University was filmed on an unseasonably warm spring day, however, the costume department had provided the high school extras with cold-weather clothing. The real Columbia University students can be seen in the background wearing shorts and t-shirts by contrast. (00:05:35)
Other mistake: When Helena Bonham Carter removes the necklace from its case, the clasp of the necklace is obviously closed (or at least it should be-otherwise it would slip inside the case itself from the raised mount that it is kept on in the case when the case is being carried) ; she is carrying the top of the necklace (where the clasp is) in her left hand while her right hand carries the bottom of the necklace. Had the clasp been open in the case, her arm and hand motion when she picks it up with her fingers would not have been so smooth. She goes over to Anne Hathaway with the clasp obviously opened (because we see her put the necklace around Hathaway's neck rather than over Hathaway's head) and then she closes it. When she tries to open it a few minutes later the security guard informs her that she cannot open it; that it can only be opened with a special security magnet - which he then proceeds to use to unlock the clasp. In other words, the necklace would have needed to be opened by the security guard to begin with before Helen Bonham Carter could put it around Anne Hathaway's neck. (01:01:05)