Continuity mistake: When they realize the signal's counting prime numbers, watch the man in the red shirt behind Ellie when 11's being counted off. He's counting on his fingers, fills up his right hand, and moves to his left. The angle then changes to a closer shot, and his left hand is now curled up, with no numbers counted off on it at all, and he continues on his right.
Jon Sandys
2nd Sep 2003