Revealing mistake: When Dana is walking down one hall with Leroy and a bottle of champagne, the exit sign is reversed. (00:53:05)
Revealing mistake: When Alex and Megan find the dead bodies in the dining hall, in the closeup shot of Dana, her neck pulsates. (01:09:05)
Revealing mistake: Toward the end of the movie, when Gallagher is trying to escape the elevator through the top, the wires for the Tunneler Puppet are visible in one shot. (01:16:10)
Revealing mistake: Dana enters her room and sees Neal sitting in the chair. Right at the part where she tells him that he can fool the others but not fool her, there's some smoke in the close up shot of Neal's face.
