Continuity mistake: When playing Monopoly, Nuclear Biff rolls double 6. In the next shot, the dice change position. You can also see a 1 showing on one of the dice indicating the top number is not a 6 (it's a 2).
Continuity mistake: When Greyson is using the rental scan on his tablet, he's sitting straight up. In the next shot, he's bent over as he leans in to start the scan, but then he's back to sitting straight up. He switches position based on the camera angle.
Answer: He was granted a full pardon.