Character mistake: Kendall signs Mr. Bitters' shirt with his own initials "KS", but his character's initials are "KK" for Kendall Knight. (00:02:45)
Big Brother - S3-E15
Character mistake: During "Somebody That I Used to Know," Blaine puts down his satchel. At the end of the song, he leaves the auditorium without picking it back up.
Cat on a Hot Steel Beam - S1-E60
Character mistake: As the fire truck darts out from a back alley, the sign on a nearby gift shop window reads "gift's" when it should be "gifts".