Revealing mistake: When Sonny is on the payphone, you can see Julian mouthing something to the guy on the payphone behind Adam. The guy is giving him instructions.
Other mistake: When the nanny comes home with the tags, they call Jewel to get hers first. Jewel has a penis.
Continuity mistake: Professor Sheldon 'Shelly' Oberon sprains his right ankle when escaping the baboons by jumping to another bridge. Ming Fleetfoot wraps his left ankle later on when they are by the river. (01:11:38 - 01:14:00)
Continuity mistake: During the detention scene, the teacher comes in and you can see there isn't anything on his rear end. As he leaves, you can see toilet paper hanging from his rear. This was because a scene never made it into the movie where the teacher's office is in the mens restroom. Also confirmed on cast commentary.
Factual error: They are present at Frankfurt, Germany. But with a closer look you see a cathedral at the right side. This cathedral and the central station are located in Cologne, Germany - they are about 220 km apart. (01:04:15)
Character mistake: On the day Rebecca arrives home, Junior Douglas says that he was "Valedictorian, Class of '95." Earlier, Drago talked of almost killing Running Buffalo "during that trouble back in the '40's," which would have been about 50 years earlier. That would mean Drago and McLintock were fighting Indians when they were babies, or possibly before they were born!
Continuity mistake: During the fight between Aslo and Silas, Aslo is seen lying on his back in a closeup. But when the shot changes to a wide shot, he is suddenly on all fours.
Audio problem: When Britney Spears gets pushed into the Pit of Death, you hear her talk and scream but her lips are not moving.
Continuity mistake: When Sam and Anton are finished fighting (Anton is in an upper-body cast), the arm support on his right keeps changing. First it's a short piece coming from the elbow, then it is a long piece coming from the side, and then back again.
Continuity mistake: William H. Macy makes dinner plans with the Mayor and writes "Dinner with the Mayor" on the dry erase board in his office. He writes "Dinner w/ the Mayor" in the "Tuesday" slot. Then an intern comes in and accidentally wipes the appointment off the board with her shirt. Macy yells at her and tells her to rewrite the appointment on the board. The whole premise of the joke and pretty big part of the movie is that the intern rewrites the appointment in the wrong day, thereby causing the Hollywood people to miss dinner, enrage the Mayor and his wife and have the town turn on them. When the girl walks away however, the appointment is clearly rewritten in the correct day (Tuesday). This ruins the whole misunderstanding because although the appointment is in the wrong day later in the movie, at the moment the joke is supposed to be set in motion, there is no mistake.
Continuity mistake: A couple of scenes after the baker's wife ripped off most of Rapunzel's hair, it has grown back to full length so that the prince can climb up to the tower on it.
Factual error: Opening scene shows NYC 1962 as a 1964 Chevy Impala rolls by.
Continuity mistake: In the scene where grandpa is attempting to ship his grandson to his dad in a cardboard box, grandpa says to the two ladies who are objecting to his requests "well give me a pen, and we'll write FRAGILE on it." Shortly before he says that, the box already says "FRAGILE" on the right hand side, and then 2 seconds later the writing has disappeared. (00:31:10 - 00:32:15)
Character mistake: The sign for the hotel where Jake is staying at in Mexico says Tengo Quarto's para Renta. The word is spelled wrong. It should say CUARTOS. Also, there is no apostrophe s in cuartos. It is plural, not possessive.
Continuity mistake: At the end of the scene when Homer first goes to Juan's diner, the amount of orange juice in Homer's glass changes when he and Juan introduce themselves.
Factual error: The movie is set around 1995. But the SWAT team in the movie is wearing gear from the 2000s. (MICH-2000 helmet, modular tactical vest, M4 variant with picatinny rails and scope). Plus, in a scene when the guys are shopping for a taser (gun shop scene), some of the rifles on display are from 2000s era. AR-15 variants with variant stock, foregrip and picatinny rail. Those style of weapon system were unheard of in early 90s. Even Special Forces just adopted it by the late 90s.
Visible crew/equipment: When Officer Romero and Arthur are alone in the house, handcuffed to the brass shelving unit, as she says, "Help me or I will crush you like a damn bug," a crewmember wearing glasses and a blue shirt is seen crouching on the floor, at the bottom right of the screen. (00:53:05)
Visible crew/equipment: As Sam and Rhonda have Fiona's car confiscated, when Fiona runs out shouting, "I can pay for those parking tickets!" the crew's black mat is laid out on the walkway, but in the overhead shot when she tries to run away that mat is gone. (Visible on fullscreen DVD.) (01:28:10)
Character mistake: Selena Gomez drives into town in a fully restored 1967 Pontiac Le Mans, which is a long box shaped car. However, when confronted with Bill Murray and Adam Driver, Adam Driver complements her on her 1968 Pontiac Le Mans, which is a completely redesigned shorter curved body style. The two look nothing alike.
Continuity mistake: In the bowling alley, 'Pal' comes over to speak to Tia. During their conversation, the camera pans to Maisie throwing a bowling ball; however Tia is now sitting alone. Pal has disappeared. (00:40:10)