Gus's Dad May Have Killed an Old Guy - S2-E10
Continuity mistake: The red ball in the first scene changes position. In the close up shot, there is a green plant in front of the ball with two stems. In the next shot (from above) there is no longer a plant on that side of the red ball.
Gus's Dad May Have Killed an Old Guy - S2-E10
Continuity mistake: Gus' dad gives Shawn some money for Gus. As he hands it to Shawn it is a $50 bill, but after he gives it to Shawn it changes to a $20.
There's Something About Mira - S2-E11
Continuity mistake: While at the batting cages when Shawn and Gus are throwing balls at the PI, there are a couple of people playing catch in the background. They disappear the last time Shawn throws.
The Old and the Restless - S2-E12
Continuity mistake: When young Shawn is sitting on the bench talking to his grandpa he has a sandwich in his hands. He starts to put it on the bench to his left, the shot changes, and it is already on the bench. Then for most of the rest of the scene it is on his right until his dad arrives and he picks it up from his left.
Lights, Camera... Homicidio - S2-E13
Visible crew/equipment: When Shawn and Gus are walking and talking to Quintessa at the studio, a boom mic can been seen reflected in glass behind them. (00:13:20)
Lights, Camera... Homicidio - S2-E13
Continuity mistake: When Gus is talking to the prop guy a person can be seen walking in the background with a light - the shot changes and he walks by again.
Black and Tan: A Crime of Fashion - S2-E15
Continuity mistake: After picking up the papers and book that were dropped, Shawn is holding and looking through the book, and Emily is holding the papers. At one point Emily takes the book from Shawn and the papers she was holding disappear.
Black and Tan: A Crime of Fashion - S2-E15
Continuity mistake: When Shawn scares Emily she drops the papers and book she is holding. The book is on the bottom, but when Shawn helps her pick them up the book is on the top.
Black and Tan: A Crime of Fashion - S2-E15
Factual error: In the flashback at the beginning of the episode, Shawn is wearing a Knight Rider T-shirt. This flashback takes place in the 80's, but the art printed on the T-shirt is a picture-perfect copy of the cover art from the US DVD release of Knight Rider Season 3 - this DVD set (and the cover art style/arrangement) was not released until 2006: http://en.wikipedia.org/wiki/Knight_Rider_%28season_3%29.
Shawn (and Gus) of the Dead - S2-E16
Audio problem: After the van the Shawn and Gus are following crashes, Gus says "I'm not getting out there" but his mouth is saying something different. (00:34:15)
Shawn (and Gus) of the Dead - S2-E16
Continuity mistake: When Shawn is showing Gus the picture of him with the dinosaur he discovered, Gus' name is to the right of the photo, the next time it is seen it is below the photo.
Six Feet Under the Sea - S3-E10
Continuity mistake: As Shawn's dad is showing him how to drive the boat, he is alternately leaning against the railing with his arm outstretched, and with his arm at his side, depending on the camera angle. (00:20:25)
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)
Truer Lies - S3-E14
Continuity mistake: When Shawn and Gus are being chased in Gus' car through the alley, in one shot the car trunk opens. The next shot it is closed, then when they stop it is open again.
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)
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)
The Devil Is in the Details... And the Upstairs Bedroom - S4-E4
Continuity mistake: In one of the first shots showing Agatha's friend Lucy behind the police line, Gus is visible in the background talking before Shawn and Gus arrive at the scene. (00:03:20)
Continuity mistake: When Shawn wants Gus to throw him the baseball, the people walking in the background behind Gus keep changing between shots.
Continuity mistake: When Gus takes the Doritos bag from Shawn and sits down, every time the camera is behind Gus, the back of the bag is facing the camera, and when the camera is in front of Gus the back of the bag is also facing the camera. When Shawn stands up the bag is suddenly between Gus' legs.
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.