Continuity mistake: At the restaurant, when Bertha goes to the kitchen and speaks to Fred, the way Fred holds the sock constantly changes between cuts. (00:30:59)
Continuity mistake: In the opening scene, there are spectators and the camera zooms in on a man and woman with a Rottweiler standing next to the woman. There is a glimpse of two people past the dog. The camera briefly shifts to show a woman (Sonny) walking toward the front door, then returns to the spectators. The Rottweiler (presumably the same dog) is now standing near the left side of a different man (and is not next to the woman). (00:02:02)
Visible crew/equipment: As Max opens the bathroom door on the plane, a reflection of the crew is visible in the door. (00:50:10)
Factual error: Mallory tells Florence that the school is in Cumbria. Cumbria didn't exist in 1921. It was created in 1974 from Cumberland, Westmorland and part of Lancashire.
Continuity mistake: In the scene where Lily is hiding behind Thomas' computer desk, she uses her little Eiffel tower necklace to put inside the socket to short out the power. When she goes to put it in, you can see the computer is plugged in on the bottom socket. After a really quick cut scene, the computer is now plugged in on the top socket. (01:05:00)
Continuity mistake: Three teen boys are abducted to be killed at the church. One breaks free and finds a weapons cache and dies in that room, while his killer dies outside that room. Soon after, the preacher and his wife find the dead church member, then look into the weapons room to see two of the teen boys dead, side by side. But the second hasn't been killed yet, and dies running away from the church later, shot by the the local sheriff by mistake. (00:40:40 - 00:48:00)
Suggested correction: The second boy, the one who got shot outside, was playing dead so the church members would leave him. It is not a mistake in the movie.