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: 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)
Other mistake: If Otto's wife was in a wheelchair for 40 years, why did the house not appear to be handicap accessible? Otto hadn't touched anything in the house after her death, but the only noticeable building alteration was the low counter top in the kitchen. No permanent ramps? No stair lift?
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.
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.
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.
Other mistake: When the four 'Disruptors' that stayed buddies solve all the puzzles, they retrieve the invitation from an intricate miniature Glass Onion at the center of the box. When we see the mysterious outcast break the box open, she gets the card from a compartment on the side. While we are not privy to the inner workings of the mechanism, that's obviously not where it was supposed to be. (00:11:00)
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.
Factual error: The pub sign states "whisky" - Irish whiskey is always spelled with an E.
Suggested correction: Persse's Whiskey Company of Galway (named on the sign) used the 'Scotch' spelling on advertising mirrors and bottle labels.
Revealing mistake: The very first shot of the movie, supposedly of Anya Taylor-Joy lighting a cigarette, does not match the following shot on the pier; the cigarette appears to be black and with a brand sleeve instead of the normal one she is smoking. The background confusingly looks more like an interior than the pier she is standing on, and the lighter is a common Bic-style one instead of the Zippo she is using also later in the movie. That's because it's actually stock footage. You can literally find the clip yourself on Shutterstock and similar websites, by the description "Close-up of the silhouette of a woman's face sticking a cigarette into her lips, igniting her with a lighter, and exhaling smoke. The grim concept of the harm of smoking in a low key." (00:01:00)
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.
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)
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: 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: During the police chase at the start, when Chief Luggins begins to climb out of the driver's window, there are no spotlights on her vehicle, but in the next shot, two spotlights are suddenly mounted over the side view mirrors. (00:07:40)
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)
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: 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: 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)