Deliberate mistake: In the film, American aircraft carriers carry no fighter planes. It was a weird choice...pilots who were naval fighter pilots were edited out of the story, and Wade McClusky, who in reality was previously a fighter pilot but moved into dive bombers had his story changed for the film to have him previously had been a torpedo plane pilot instead.
Deliberate mistake: The Stan Lee cameo contains a factual error; he's checking out of the Mallrats script and rehearses his lines, but despite coming out later in the year, the movie (and therefore Lee's cameo) had already been filmed, since movie shooting ended in April. Unless we have to assume Stan Lee carried with him all the time scripts of movies he'd been in and randomly read his scenes aloud. (00:30:45)
Deliberate mistake: In the handyman's room, we see he has cameras secretly set up in the various apartments to spy on neighbors. But the placement of the camera spying on Mrs. Norris' dining room is kind-of ridiculous. It appears to be sitting out in the open on her dining room table. Sure, the handyman is a pervert, but there's no way he could get a camera onto such a spot without it being totally obvious.
Deliberate mistake: At the speed trap, Tom points his radar gun at a turtle. From his perspective, he seems to be looking through some sort of scope with cross hairs and numbers on it at the turtle to line up the beam. However, when he then looks at the radar gun at the speed indicated as 1 MP/H, there is nothing on the gun where he could have been looking through such a scope. At best, the top of the run appears to have plastic iron sites. The scoped view would not have been from the device itself perspective since it would not need cross hairs or numbers on said cross hairs as that would be for a person looking through it to have reference points. This scope view of the turtle was most likely just added by the film makers to have a better visual representation of Tom aiming the radar gun at the turtle. (00:04:29)
Deliberate mistake: The prisoners in the dark dungeon would not be able to read the letter (to Miss Dudley from Jason Flemyng that the carrier pigeon had) or see such a clear reflection by pouring water on the stone floor and holding the letter (written backwards) by the water. The room was suddenly lighter when doing so, but it wasn't clear where the light was coming from. Also, sunlight coming through the small window would not beam straight down along the wall. (00:07:23)
Deliberate mistake: Carson's [John Travolta] cat Raymond did not appear to be in the pet carrier when he was running out of the building to his car or when walking to his office and placing the carrier on the desk. (00:02:15 - 00:03:30)
Deliberate mistake: When Tree turns on the magnetic medical equipment, it's somehow strong enough to yank a big, heavy wheelchair up and pin Gregory in only a split-second, but not strong enough to instantly pull the screwdriver out of Tree's hand? Obviously this was done so Tree could have a cool moment where she lets go of the screwdriver and it impales Gregory... but it makes no real sense.
Deliberate mistake: After dropping Rick off at the set, we see Cliff driving his car back to the house to fix the antenna. View forward from inside the car, the rearview mirror is obviously missing. The next scene, outside with the car coming toward you, the rearview mirror magically reappears.
Deliberate mistake: The "CPR doll" smashed through the car's windshield, knocking out two-thirds or more of the glass. The doll would not weigh enough to break through the windshield (and maybe not even cause a hairline crack). The excessive amount of glass smashed out and the distance the doll flew before landing on the highway were obviously exaggerated for dramatic and comedic purposes. (00:47:00)
Deliberate mistake: In the lab where Jessie is working, the canister that Walter had put his bloody hand on when he dies at the end of Breaking Bad still has the bloody handprint on it from that episode. However, this part of the film takes place before that episode happens. In the behind the scenes, the director stated he didn't have the heart to remove the handprint and decided to leave it in as a little "Easter Egg"