Continuity mistake: When the man drives his car into the cornfield and hits the boy with his vehicle and rescues the mom and her son they run out of the cornfield and back to the house. After the house catches on fire they run outside and his car is parked in the driveway.
Factual error: The 'Post Office' is nothing like an English one would have been, even in a remote rural location in Victorian times. It seems to have been transposed from the American Wild West.
Revealing mistake: When Krampus walks toward Max after he yells at him to give him his family back, wires are controlling Krampus' arm. (01:24:30)
Continuity mistake: When Gordo leaves Simon and Robyn for a few minutes to handle a work thing, Simon starts mocking Gordo in his absence. Simon tells Robyn that Gordo wants to nail her and Robyn says "Stop it," but Simon continues his mocking of Gordo. At the end when Simon is listening to the recording that Gordo made of that conversation, Robyn's "Stop it" is absent.JRambo299
Deliberate mistake: When Quinn is texting the boy next door, he responds too quickly for it to be real. She sends the "So you think I can stop traffic, huh?" text and gets a response within literally two seconds. She then sends the "Did I wake you up?" text and gets two responses within five seconds. Texts usually take several seconds (at least) to be delivered and opened, so even with great service and lightning-fast fingers, this is obviously far too quick.
Continuity mistake: When the party goers are escaping, Ben begins tying the door closed, but in the next shot, there are still people running up the stairs escaping. (01:19:30)
Continuity mistake: Spoiler alert: About halfway through the movie, we see Emma Roberts coming out of the shower, and the camera focuses on the gunshot wound on her shoulder, with the round scar of the entry wound on her back, and the much rougher, ragged scar of the exit wound on her front. Then at the end of the movie, where it's revealed that Kiernan Shipka and Emma Roberts were actually playing the same character, just nine years apart, Kiernan Shipka gets shot by the police officer when he finds her in the room with the severed heads. Problem is: she was facing the officer. The scars on Emma Roberts are the wrong way around. (00:31:05 - 01:15:35)Friso94
Continuity mistake: When Griffin gets out of bed, when he hears the clown song he pushes the bed sheets forward about 3 feet from the pillow but when his dad goes into Griffin's room, the sheets have been pulled up about half that length.