Continuity mistake: At the very beginning, when Quaid has finished showering and is picking his phone, wallet, badge, keys, etc, there is a shot of his hand as it is picking up his cellphone. Cut to a wide shot of him and the objects have moved. For example, the coins have become a close cluster, his pack of cigarettes is no longer on the newspaper, and his badge has switched places with the lighter. (00:02:45)
Continuity mistake: After seeing the aborted baby, Quaid goes into the bathroom and plunges his head into water. His hair, however, is perfectly dried afterward. (00:35:35)
