Psy vs. Psy - S2-E3
Continuity mistake: When Shawn kicks over the carry-on bag at the end, it lands with the handle on top. The subsequent wide shot shows the bag with the handle on the bottom. The handle is back on top just before the bag is opened.
Psy vs. Psy - S2-E3
Continuity mistake: Shawn and Gus are in front of the Psych office talking about how the other psychic beat Shawn. There are two guys standing in the background, then in one shot there is only one, the next shot there are two again.
Chosen answer: "Psych: The Musical" was supposed to air during the regular season 7 schedule, before Chief Vick is suspended and Jules discovers Shawn's lie, but the network decided to push it back to air as a special episode, sort of as a tie in with the holiday season and a lead in to season 8, which was to begin only a couple of months later.