Character mistake: When Gus goes to check the source of the creepy phone call, he finds Shawn who immediately ends the call before saying anything. Later in the episode, Haversham says he heard Shawn say "Gus?" before ending the call.
Character mistake: When Shawn looks at Curtis Stanzen's file in Leo Quinn's office, guilty is misspelled. It says "gulity". (01:30:00)
Extradition: British Columbia - S4-E1
Character mistake: When Shawn is checking Ed's book of valuables, the crown that Shawn thinks Despereaux will steal, has a listed value of "950,000 - 1,000,00,000 USD." I guess it's really, really(!) valuable, enough that a whole new numbering system was made up for it. (00:30:55)
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.