Deliberate mistake: *SPOILER ALERT* Behind T-Bag is the actor who plays Lechero, and Lechero had just died in the episode. The person was not Lechero, but maybe they didn't have another extra at hand to replace him. 'Time 1' and 'Time 2' are taken from Netflix at the time this was posted. (00:29:46 - 00:30:25)
Visible crew/equipment: When McGrady's dad is told to get out of there, a camera shadow is seen to move over the guard's uniform. (00:14:20)
Continuity mistake: When Mahone is in the bar at the start, his hand is constantly changing from up at his mouth to down by his side. (00:09:50)
Continuity mistake: The shadows and lighting change throughout the scene with T-bag giving the money to the prisoners. At one point he is in shadow, the next full sun.
Answer: Because of coincidence.