When Sophie first arrives, Ellen says she has two months left. When Sophie is later put in the circle, they say Sophie's been there for over a month. Right after that, as they are seeing people leave, they mention Ellen leaving in two months again.
One of the slides in Dr. Hail's presentation at the seminar in L.A. says "Responsability". The correct spelling is "Responsibility".
Peter Stormare plays Dr. Arthur Hail, but closing credits list the character's name as Dr. Norman Hail. Nowhere in the film is he ever called Norman.