Revealing mistake: Any time any character is driving a Suburban, or any other vehicle with a column mounted shift lever, the shifter is in park while they appear to be driving.
Orange Blossom Ice Cream - S7-E3
Revealing mistake: Right after Jane and Lisbon rumble Erica Flynn and send video of her being arrested back to the FBI, Cho enters and asks to speak with Vega. In the shot of Vega sitting down, one of the computers in the office (centre of frame) has an Apple logo on the back that the production team forgot to cover up with a sticker like all the others.
Revealing mistake: At the very beginning, there's a square piece of board on the dead body's back, on which to support the knife.