Continuity mistake: When Darien wakes up, following the RNA injection, with his brother's memories, his hair restyles itself several times between takes. (00:11:25)
Continuity mistake: The cut on Darien's forehead changes positions, then vanishes the same day, after he goes home to make the video tape. (00:24:20)
Germ Theory - S2-E11
Continuity mistake: When Hobbes enters Claire's lab, the wall clock (which we can see is running) reads 9:15. Four minutes of continuous scene later, though, it's still 9:15 - and the clock is still running. (00:10:00)
Continuity mistake: The bullet holes in the side of Hobbes' van change positions, disappear and re-appear throughout the episode. (00:32:40)
Continuity mistake: Early in the first season it was established that Darien's parents died in an accident, and that he and his brother were raised by an aunt and uncle. But here, Darien's father is alive, is said to have "disappeared" years before, and there's no mention of the accident he "died" in.
Continuity mistake: The establishing shot of the Agency's headquarters building zooms in on 3 tall, narrow windows recessed into a brick wall. We then cut to an interior view - of several wide, continuous windows without any recesses. They don't match the exterior windows at all. (00:07:30)
Continuity mistake: In the nuclear power plant, Darien picks up the technician's box of snacks, holding it by the narrow edge. Then the shot cuts, and he's instantly holding it with his hand spread across the wide front of the box instead. (00:35:30)
