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)