Continuity mistake: At the end of the episode when Shawn and Gus are at the new Psych office, Shawn puts some scissors in a cup with pencils. The shot changes and the scissors have changed position.
Continuity mistake: During the first scene in Gus' office the door is open in some shots and closed in others.
Extradition: British Columbia - S4-E1
Continuity mistake: When Shawn flashes back to remember where he has seen Pierre Desperaux, he flashes on a photo of Pierre in Lassie's apartment next to Ernesto Chavez (on the right) on Lassie's wall. Going back to Season 3, Episode 11, when in Lassie's apartment, there is no photo next to Ernesto's photo. (00:03:20)
Continuity mistake: Just before Gus is awoken by noises in his apartment, there is a shot of his alarm clock. The time shows 6:07PM. When he gets out of bed, the clock says 7:01 (cannot determine if it is AM or PM). Even assuming he just lay in bed for an extra hour, he then tracks down Lassie who is about to eat lunch. (00:27:00)
Woman Seeking Dead Husband - Smokers Okay, No Pets - S1-E4
Continuity mistake: When the bank robber enters the mausoleum, his hands are empty. When Raylene points her gun at everyone, he raises empty hands. After Lassie and Juliet arrest David and Raylene, the bank robber is holding a slushie cup. (00:36:40 - 00:37:30)
Six Feet Under the Sea - S3-E10
Continuity mistake: When Shawn and Gus are driving the boat at night, we see the coordinates on the GPS tracker - two seconds later (real time, as they are talking), the coordinates have changed; now they are about 37 miles from where they were, so they must have hit 65,000 mph for those 2 seconds. In case my math needs correcting, the first set is 34 06' 50.25" N x 120 17' 41.31" W and the second set is 33 57' 40.21" N x 119 35' 56.58" W. (00:21:55)
From the Earth to Starbucks - S1-E10
Continuity mistake: As Shawn and Gus walk up the stairs to the courthouse, there are only two men standing beside the steps, at the fence. The camera angle changes and there are three completely different people standing there. (00:01:15)
He Loves Me, He Loves Me Not, He Loves Me, Oops He's Dead - S1-E11
Continuity mistake: When Shawn and Gus are back at the office after the sorority ghost sighting, Gus talks to Sean from his desk. Shawn is just on Gus' right and Gus' head is turned slightly towards him. The camera angle changes and Gus is turned left (Shawn has not moved). Then Gus is again looking left. (00:16:40)
Continuity mistake: When Shawn sees the box with the dead doctor's files, Regina Kane's file is visible halfway back in the box. He then tells Gus, "All we have to do is find Regina's." (Which he was looking straight at, but let's call that a character mistake.) A few moments later, we cut back to Shawn and Gus and Shawn finds her file in the front of the box. (00:37:00 - 00:37:40)
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.