Continuity mistake: When Knowle Rohrer is talking with Agent Doggett face to face in a separate room about the super-soldier project, he is wearing a red FBI badge, but in the previous scene when he came to visit Doggett, he was wearing a regular FBI badge.
Continuity mistake: When Agent Reyes is aiming at the oncoming car of a ranger, in the front shot the windscreen of the car is completely covered with dirt and fully opaque, while filmed from the ranger's side the windscreen seems to be transparent and relatively clean.
Continuity mistake: Just before Skinner shoots Alex Krycek in the head, Alex is lying weakly on the ground, having already been shot twice. However, as Skinner makes the kill shot, Alex is suddenly standing and falls to the ground upon impact of the bullet, with no time (or strength) for him to have risen. Also, the last shot of the dead Alex shows his face and his nostrils flare from breathing.