Revealing mistakes: Midway through the film Peter Sanderson and Frank Sedman are conferring with a computer whiz. When we see a full view of the table that the men are standing around it's not Sedman but Tom Skerritt's stand-in - his face is in full view.
Revealing mistakes: When Erica is shown playing Super Mario Brothers 3 on a PC, the moves she makes with the joystick as well as her keyboard tapping are inconsistent with what is shown on the PC monitor. In the next scene, she moves away from the PC but the game is still playing by itself.