The Night of the Big Blackmail - S4-E1
Continuity mistake: Before and after the first freeze frame, West's hair is combed from the right side to left. During the next scene when West's hat comes off during the fight, his hair is combed from the left side. In the next scene in the boxcar, his hair is back to being combed from the right. In the last scene of this episode when West is in the boxcar, he has a completely different hair cut. It is much shorter than in the previous scene, very flat looking, and is parted on the left. This last shot makes Mr. West appear to have a receding hairline.
The Night of the Doomsday Formula - S4-E2
Revealing mistake: When West rescues the doctor's daughter from the flames by swinging down from his rope, the face of the stuntman playing the daughter for this scene is obvious.
The Night of the Juggernaut - S4-E3
Continuity mistake: In the last scene right before West walks into the boxcar, the front of the train shows the number 16, and the square area around the front light is grey with swirl designs above and below the light. At the end of this scene, the last shot is of the front of the train, and it is showing the number 8 with the square area around the front light is red.
The Night of the Gruesome Games - S4-E5
Revealing mistake: Just before Doctor Raker gets to the cliff before falling, there is a jet airliner seen in the sky just over his right shoulder.
The Night of the Gruesome Games - S4-E5
Visible crew/equipment: About halfway through this episode as West is fighting two men in a bedroom, reflected In the mirror you can see a camera man (wearing a short sleeve white shirt and dark pants).
The Night of the Gruesome Games - S4-E5
Revealing mistake: Midway in this episode, West is fighting two men in a bedroom. One of them is pushed into the green chest of drawers and breaks it. It is obviously a prop, because the front is a flat piece of painted wood to look like drawers; there are no drawers when this piece falls apart.
The Night of the Gruesome Games - S4-E5
Revealing mistake: The guide wire of the knife Dr. Raker throws at West is visible, as is the hole in the wall where the knife point lands.
The Night of the Gruesome Games - S4-E5
Visible crew/equipment: A film crew member's shadow is visible to the left in the scene of West getting his horse back on its feet.
The Night of the Kraken - S4-E6
Continuity mistake: The first time we see the bartender, he has a rip in his shirt on the back side under his right shoulder blade. In all the other scenes, the rip no longer shows.
The Night of the Kraken - S4-E6
Continuity mistake: When Jose' Aguila pulls down the net, he is in front of the bar. The next shot he is instantly punching a bad guy in front of a window, which is several yards from where he was at the bar.
The Night of the Kraken - S4-E6
Continuity mistake: During the bar fight, Aguila and the goons he is fighting disappear from the scene, showing only West fighting some bad guys. Instantly Aguila appears in the exact same area where West was fighting.
The Night of the Kraken - S4-E6
Other mistake: While walking on the waterfront after the bar fight, West and Aguila's clothes are dry where moments before they dove out a window into the ocean.
The Night of the Kraken - S4-E6
Continuity mistake: While struggling under water with the kraken, West surfaces, then the next shot shows West deep underwater and breaking the surface again.
The Night of the Kraken - S4-E6
Factual error: West and Artie are trying to move a cabinet from the wall. A closeup shot shows West's left hand entering from the right side of the shot to press a button that allows a secret panel to open. Unless West twisted his left hand 180°, then him pressing the button as shown is not possible.
The Night of the Kraken - S4-E6
Revealing mistake: Bubbles from the underwater camera crew are visible as West swims wearing the experimental diving gear.
The Night of the Kraken - S4-E6
Revealing mistake: The strings controlling the kraken's tentacles are visible as it attacks West and Aguila.
The Night of the Fugitives - S4-E7
Continuity mistake: West uses a chandelier to knock down a thug wearing a brown vest against the opposite wall in the Saloon. When West gets up, the thug is now lying next to West and wears a green vest rather than brown, and is also closer to the Saloon's bar.
The Night of the Fugitives - S4-E7
Continuity mistake: David Desmond's cigar instantly changes from being elevated in the facial close ups to being at a lower angle in the shots from behind his right shoulder.
The Night of the Fugitives - S4-E7
Continuity mistake: Monk sees West in a mirror escaping from behind the hotel's door. The immediate next shot shows West escaping again.
The Night of the Fugitives - S4-E7
Revealing mistake: Ross Martin's stunt double is obvious after Hallelujah Harry's coach begins exploding. The stunt man looks nothing like Martin and has an obvious bald spot on his head, whereas Martin did not.