When Denver Leonard is on the porch with the others, as he asks them to go back inside, he puts his arm and turns one of the actors twice.
Immediately after Jefferson Pike shoots himself, there is no hole in his pant leg, nor is there any blood. The hole and blood appear when he walks toward the car to return the gun.
When Jefferson Pike tries to get into Denver Leonard's car, he finds it is locked, but reaches through the open window and unlocks the door. After Pike's shooting, Leonard comes out and drives away, but when he unlocks the door, gets in and drives off, the window is no longer open.
Denver Leonard's car registration, mounted on the steering column, reads that his license plate is "NFL 252." However, his actual license plate is "SDL 689." This same "disconnect" between the registration (again NFL 252) and the actual plate will happen again in The Case of the Barefaced Witness (1961). There, the actual plate will be RKM 126.
Around 15 minutes into the show, Jeff looks at his pocket watch and there's a close-up of the watch face. The second hand of the watch doesn't move, meaning it's a still picture.
On the registration paperwork for the 1959 Buick, the word convertible is misspelled as "convertable".
When Fred Pike is watching the film of his own performance, the film feeding into the projector is clear, while the actual picture of the skating arena on the screen is always at least half dark, so the film feeding the projector should have been dark, not clear.
When Perry is talking to Asa about his ice skating investment, you can see smoke drifting in front of the camera. Someone off screen was clearly smoking.
No one comes out of the restaurant to investigate after the gun is fired in the parking lot.
When Lt. Tragg describes the murder weapon to Perry, he says it was a shotgun. When Perry questions this, Tragg says it was used as a "club". Tragg should have referred to it by the legal term "bludgeon".
When Vita Culver jumps up, interrupting the court proceedings by yelling to stop, the judge doesn't react at all. In reality, any judge, if not verbally admonishing the interrupter, would at least pound the gavel to restore order.