Factual error: Tiffany asks a guard where he would go if he could travel back in time. He says he would return to 1999 to attend a Judas Priest concert he missed. He says he wasn't able to get close to Rob Halford. The problem is Rob Halford was not the lead singer of Judas Priest in 1999. Tim 'Ripper' Owens was.
Character mistake: At the end of the episode when Maria is framed for the prison panty business and told to expect an additional 3-5 years on her sentence she cries saying that her daughter Pepa will be in kindergarten by the time she gets out. However in season 2 episode 12 Maria tells Piper that she still has 6 years left on her sentence. This means that even without the extended sentence her baby would have been well past kindergarten age by the time she was released, so taking the extra 3-5 years into account, Pepa could be almost finished in elementary school by the time her mother got out of prison.
Continuity mistake: In season 3 Baxter Bayley's uniform reads C. Bayley. In season 4 it reads B. Bayley.