Deliberate mistake: On Carolyn's first day, the scene is set by showing the exterior of a large square office building supposedly in Detroit, but when she is riding up the exterior elevator, it is obvious that the building outside is the Bonaventure in Los Angeles.
Deliberate mistake: In the scene where the FBI agents are transporting Lester Cowans in a car and telling him all his friends have confessed, for about three seconds the scenery goes by backwards. For some reason, the shot is played in reverse.
Deliberate mistake: After Doug finds where Minuti was killed and set on fire, he walks over to a dock where he sees Minuti's arm being eaten by alligators. Minuti had been dumped in the water 4 days prior, yet his hand is perfectly intact with no signs of burning, bite marks or weather/water damage of any kind.
Deliberate mistake: Throughout the film, scenes of several Cole Porter productions are shown being performed. These scenes all contain a well-known musical number. Two scenes in particular (after the Alanis Morissette number and immediately after the "So in Love" duet) end with the lead singer/singers bowing to the audience and then waving the other cast members on stage to take a company bow. The problem is that neither of those numbers appear at the end of the shows being "performed." The "So in Love" duet, for example, most definitely appears in the musical "Kiss Me, Kate" well before the Act Two finale. I assume that these mistakes were filmed deliberately to emphasize the importance of the songs in question, but they are still errors.
Deliberate mistake: In order to get to Julius Caesar and evade her nasty brother Ptolemy's assassins, Cleopatra concealed herself in a rug that she has a slave carry to Caesar. Look at the furled rug the slave carries on his shoulder. Then watch Cleopatra fall out as the slave tosses the rug to the floor and unfurls it. The slave would have needed wall-to-wall carpeting to hide her.
Deliberate mistake: In the scene inside General Kohler's command center when Kohler is giving Colonel Hessler a tour of the war room he points out to Hessler a clock on the wall whose increments represent 1 hour and that the attack has to be over within so many hours. Later in the movie, just when the attack starts, this dormant clock's hand immediately springs forward and ticks through 2 increments, thus representing 2 hours passing in 2 seconds.
Deliberate mistake: When the crew are piling into their jeep to ride out to their aircraft, the gunners ask the officers what their target is, and are disgusted to hear that it is Bremen, a tough one. The gunners should know their target already. Gunners were briefed on their target, and told what kind of fighter opposition to expect.
Deliberate mistake: In the film, Martha Jefferson visits Thomas in Philadelphia. While this is factually inaccurate (she was actually at home recovering from a miscarriage), it was changed for the sake of drama.
Deliberate mistake: The first time the warriors ride out during the full moon, the shot of the moon shows that it is in the phase of "half moon".
Deliberate mistake: There is blood all over the back of the couch that's supposed to be from the neck cutting, however there is not a trace of blood on May's dress or anywhere else but her hands. (01:13:30)
Deliberate mistake: While the mouse is walking on Dumbo's trunk, there is a jump in the animation. He's facing Dumbo at one point, then all of the sudden he is in a different position and is facing the other way (this all occurring in the same shot). Look for it before the mouse says, "Dumbo, the great!"
Deliberate mistake: During the scene on the train in lounge car, a picture on the wall prominently shows an ALCO PA locomotive. The movie was set in 1945, but this locomotive was first produced in 1947.
Deliberate mistake: The two princesses do not age, despite the film's story occurring over several years.
Deliberate mistake: When "C" and Jane are walking home together and Jane pronounces "C's" entire name she says his first name Calogero as well as his last name Anello but he never told her his last name he only told her his first name when they met.
Deliberate mistake: When Henry Fonda decides to recreate the old witness' ability to get to the door in 15 seconds, he asks another juror to time his walk. The scene never cuts away, but the juror who times it says it took 41 seconds when in reality it takes exactly 31 seconds, you can time it.
Deliberate mistake: When Harrison Ford and Mary Lynn Rajskub are crossing the tracks, its Rajskub who's driving the car, not Ford. This is because the filmmakers originally had Rajskub driving the entire way. They later refilmed the drive with Ford driving, but kept the shot of them crossing the tracks the same. Ford and director Richard Loncraine confirm this on the special features of the DVD.
Deliberate mistake: In countless shots showing Japanese, and some shots showing Americans, being shot, take notice of the ground that they stand on. Almost every time a bullet(s) will hit below them at their feet, yet they still fall dead. In some shots even, there is a continuous line of shots from a single shooter, hitting the ground, yet numerous Japanese soldiers fall dead.
Deliberate mistake: At or near the beginning there is a scene with autumn leaves. The colours and amount are just not consistent with the date of September 11. They seem to be about 3 or 4 weeks ahead of schedule.
Deliberate mistake: When the rocket (a replica of an Atlas booster) launches, it makes it all the way to orbit in one piece. In reality the Atlas was a two-stage rocket, and the first stage would've been jettisoned long before reaching orbital velocity. (Undoubtedly the filmmakers decided to fudge this, to avoid dealing with the issue that the rocket didn't launch over the ocean, and the first stage would've fallen onto some innocent bystander's property.).
Deliberate mistake: Just before Donald has a fight with Jack at the end of the film, we see Donald jogging down a flight of stairs to escape the building. Then after a bit of a punch up with Jack, we see Donald running back up the same staircase to escape Jack, but when he reaches the top it turns into a dead end. There is nowhere that Donald could have came from when we see him coming down the stairs. (01:19:35 - 01:20:35)