When Shawn and Gus are taking Dwayne Tanncann to the police station in the scene right before they reach the station, the car shown driven by Gus has only one person in it rather than three and also the car is the newer model of ECHO than the one that Gus owns, then in the next scene the actual car is shown.
In the opening scene, young Gus is eating an ice cream cone, and the ice cream is down to the cone. Shawn's father walks in front of him and sits down. Gus's cone now has a full scoop on the top. In the final shot, the full scoop is gone again.
When Shawn and Gus get into Gus' car at the diner, both front seats have head rests. The head rests disappear once they start driving.
When Juliet gets up to leave the diner, she places her hand on the evidence folder containing forms and pictures. She places her hand on a typed form, which is on top of the folder. The camera angle changes and the typed form is gone, replaced by a photograph.
When Shawn, Gus, and Tancana jump off the boat, it's obviously it's the stunt men and not the actors who jump.
Lassiter tells Shawn and Gus: "You are, in no uncertain terms, to make any physical contact with this man." This is essentially telling them, "Make physical contact with this man." He should have said, "You are NOT to make any physical contact with this man."
On the boat, just as the guys are jumping overboard, Tancana can be seen climbing the rails and a microphone body pack and wire is visible on his belt.
Approx 21 minutes in.
When O'Hara is timing herself stripping her weapon down and rebuilding it, she would unload and clear the weapon before starting her timer. Every cop is taught that in the academy.