Continuity mistake: At the beginning when the lady at check in is passed out on the floor, she is right up against the desk, but when Lois goes behind to tend to her, she is further away from the desk, and closer to the wall.
Continuity mistake: The mirror that the gentleman looks at to see if he is being attacked from behind changes completely when in a close-up, from a circular mirror to a more triangular one. (00:04:34)