Character mistake: The officers count the inmates and say there's 10 missing. There are indeed 10 inmates hiding in the pool. However, Pennsatucky and Chang had escaped the prison. The officers counted Linda as an inmate, who had been hiding in Litchfield the whole season, and wasn't on the list. That would make it 11 people missing, not 10.
Character mistake: Lance and May walk into a bar in Massachusetts. As they enter, the camera pans and shows a large banner on the front window. The banner is advertising "game day" food and drinks. In very large letters the banner shows Boston Red Socks. The actual correct spelling is Boston Red Sox. (00:05:45)