Character mistake: When Mikey looks at the Picture Day schedule, he points out that 4th grade is going last. However, the schedule says they are after 3rd grade and before 5th grade, actually making them fifth. The faculty is actually listed last on the schedule.
Character mistake: When the kids are walking through the hallway, on the magician's poster, it says that he does Bar Mitzvahs. But the 'z' is missing, so it says Bar Mitvahs.
The Madness of King Bob - S4-E9
Character mistake: Whenever the Hustler Kid delivers Randall's prize in the beginning, he says, "Grand prize delivery for Mr. Randall C. Weemes." But Randall's middle initial is J.