Continuity: When the fake Donovan is trying to rescue Julie, he is shot from behind. But in the next shot, the scorch mark is on his chest.

Plot hole: Diana manages to escape at the end by stealing a shuttlecraft. But how did she manage to get there, when most of the mothership (and certainly the landing bay) was contaminated with red dust?

Revealing: During the final battle in the mothership hangar, Donovan shoots a Visitor soldier who falls off his catwalk onto a transporter. When he impacts, a styrofoam block used to cushion his fall bounces off the roof.

Revealing: During the title sequence when Blair Tefkin's name comes up, Mike Donovan is riding a horse. A Visitor craft passes overhead and shoots at Donovan, but the laser appears out of nowhere instead of from the craft.

Revealing: When Kyle, Elizabeth and Robin are in the truck being chased by Mr. Chiang, in all the outside shots of the truck it is very easy to see that all three of them have been replaced by doubles.