Continuity mistake: When Billy and Chris are placing the pigs blood above the stage, Billy spills three drops of blood onto Chris' torch, but in the next shot there is only one drop on it. (00:46:00)
Visible crew/equipment: When Peck is falling down the stairs with the kid, you can see the back pad through his coat.
Continuity mistake: When Mrs. Hallet goes to retrieve the rubber seals from the cellar, she opens the trap door and the diagonal wood creates "Z" bracing; but in the next shot, as Hallet heads down the stairs, the diagonal wood cross brace is now attached to the door in the opposite direction, making a backwards "Z" bracing. None are flipped shots. (00:27:30)
Continuity mistake: When Christella is slapped by the possessed Ike, her pose changes between shots.