Factual error: The story is set in 1976. "Funkytown" is used in the movie and the end titles. The song was not released until 1980.
Continuity mistake: At 00:41:28, When Otto sits in his car, the steering wheel has no logo of the car's brand, but later on 01:08:45 the car's brand (Chevrolet) is visible when Marisol drives the car. (00:41:28 - 01:08:45)
Continuity mistake: In the beginning of the movie, Mavis stares at the window. When Drac sings to her, the window is closed in the first shot, but in the next shot it's opened. (00:01:00)
Factual error: The opening states the location as Bristol, England. Santa is drinking in a pub on Shirely Street (neither the pub or the street exist in Bristol), then shortly after is shown leaving from the rooftop, on his sleigh, with multiple high rise buildings in the background. Bristol does not have high rise buildings in the main city centre, only a few blocks of flats, which all have flat roof tops, not like those depicted.
Continuity mistake: When Daniel Radcliffe presents a special item he has put on white gloves, then a second later his gloves disappear. He no longer handles the item with gloves throughout the rest of the movie.
Visible crew/equipment: During the flashmob, there are people walking toward the camera while dancing on the street. The shadow of the steadycam filming the scene is left of screen.
Continuity mistake: Towards the end of the movie, after the baseball game they go to the blue Chevy truck. One scene shows the blue truck with wheels from a Toyota Tacoma, then seconds later shows a different set of wheels on it.
Factual error: The pub sign states "whisky" - Irish whiskey is always spelled with an E.
Continuity mistake: The first time we see the scene of Birdie sitting poolside waxing about her and Miles' fame, she brings her left hand up to hold down the side of her large hat, which obscures the camera from seeing Ms. Brand sitting down next to her, and when done speaking she pulls the hat down from the brim. When the scene is shown later a second time from Brand's point of view, when Birdie is talking she isn't holding the side of her hat, and takes it off from the top.
Other mistake: In the hot dog finger universe, everyone uses their feet for dexterous things, like playing the piano...but the pianos themselves are still designed exactly like our universe, at waist height where it's convenient for playing with hands, but very uncomfortable to play with your feet.
Character mistake: After the math club students, in unison, cited pi to 3.141592, Percy continued with "65839" - but only the "65" are correct. He should have said "65358..." before being cut off (or "65359" if he was rounding up the last "89793238"). Even though the movie is classified as a comedy, Percy was showing off, but he was wrong. Charlie, Math Club Advisor, also committed a mistake because he stopped Percy by saying "Percy, we got it. Good" (as though Percy was correct). (00:04:29)
Continuity mistake: When Nick and Javi switch shoes, the camera shot on the floor shows that the shoes they have already switched are on their right feet. When they switch permanently, they both give each other a right shoe.
Continuity mistake: At the pleasure island before Lampwick gets into the wheel of fortune, he has his glass full of beer, then it is empty, then full again.
Continuity mistake: When Sarah fires at the jeep chasing them she brings the weapon back in with the slide in the normal position, in the next shot it is in the locked back empty position. (01:26:50)
Character mistake: The 911 operator told Margot, "He [intruder Griffin] sounds harmless to me" and Margot said, "Fine", ending the 911 call. The 911 operator should follow protocol for an intruder (especially since there was the possibility of a another intruder in the house), not make a subjective assessment of the situation based on the conversation between the resident and the intruder. (00:30:15)
Continuity mistake: In a pivotal scene in the middle of the film, Josh and his stepmother Constance are having a conversation about how Lyle has helped Josh adapt to life in New York City. In the background, the same woman can be seen walking past them multiple times. She is wearing an open gray sweater with an orange shirt.
Factual error: Robert and Giselle have their belongings shipped to their new home at "18 Honey Bee Trail, Monroeville NY 10960." Monroeville is fictitious but the 10960 ZIP Code belongs to Nyack, New York. (00:00:04)
Continuity mistake: During appetizers, John Leguizamo's assistant puts her work phone on the table to let him know she is resigning. Leguizamo is holding his glass when the camera is behind him, and a spoon when he's seen from the front. (00:13:10)
Factual error: In the timelapse footage showing the street outside Bob's Restaurant, the shadows are moving in the wrong direction. In the northern hemisphere, shadows go clockwise. (00:13:46)
Other mistake: Food products used for a snowman's eyes, nose, and mouth (olives, cucumber, and ketchup, respectively) do not stay intact or unchanged over a 1-2 day period, if at all. [The idea is too absurd to categorize as a "deliberate mistake."] (00:48:33 - 00:57:00)