Other mistake: The opening credits for season 5 show June coming out of the front door with a pitcher of what looks like iced tea, and calling for Ward, Wally and Beaver who are all working outside. But the door opens by itself as she comes out, and then closes by itself behind her. If the entire family is outside, who opened and closed the door?
The Rex Montana Story - S1-E35
Revealing mistake: When Flint follows the Indians, there's a strong wind blowing. But the two puffy clouds in the backdrop sky never move.
The Case of the Lucky Loser - S2-E2
Visible crew/equipment: After leaving her husband at train station, Harriet takes a cab to meet a man at a cabin. After a few mins, she takes the man's car to go home. As she drives away, there's a reflection of a man, in suit with glasses (possibly the director) standing offscreen. (00:05:20)
Three Bells to Perdido - S1-E1
Visible crew/equipment: When Paladin talks to the ranchers, two equipment shadows are moving on the wall at the upper left of the screen. (00:03:00)
Visible crew/equipment: Diamond parks outside the apartment house, and when he opens the car door, it mirrors several stage lights and reflectors.
The Resurrection of Joe November - S3-E24
Continuity mistake: The confetti and ribbons that fall on the coffin change their configuration with each new camera angle.
Visible crew/equipment: There is a shot of the outside of the tavern (used in several chapters) where Zorro jumps towards Tornado. As the two walk away, a hand can be seen hiding behind the wall where Tornado was standing.