Days of Future Past: Part 1 - S1-E11
Continuity mistake: When Bishop is holding out his ID card for the Sentinel to scan, the card is gray with a red stripe on top, a lighter gray stripe underneath it, and a white mark underneath that. When the shot changes, the entire card is the same shade of gray. Additionally, in some of the shots of Bishop holding out the card, the he is wearing the temporal band on his arm that he doesn't receive until a few minutes later in the episode. (00:04:55)