The Night of the Bubbling Death - S3-E1
Revealing mistake: As West drags the body of a bad guy out of the scene, the supposedly unconscious man is holding his head up so as not to have his head dragged through the dirt. A truly unconscious person's head would flop back on to the ground.
The Night of the Brain - S2-E21
Revealing mistake: Mr. Braine screams as his steam-powered chair crashes into the bandstand. If you look closely at the next shot, just before the explosion, you can see that the dummy now in the chair has its head bowed forward. It also has light brown hair, rather than Mr. Braine's silver hair. (00:47:10)
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 Brain - S2-E21
Revealing mistake: When Gordon is looking outside on their train car platform, it is obvious the background desert scrub is a painted scenery flat.
The Night of Miguelito's Revenge - S4-E12
Revealing mistake: An obvious dummy floats out of the underwater coffin after West pops open the top of the coffin.
The Night of the Camera - S4-E10
Revealing mistake: As Bosley Cranston fights the bad guy, Pat Paulsen's stunt double does not look like Paulsen - the stunt double is much younger looking.
The Night of the Big Blast - S2-E4
Revealing mistake: It is obviously a dummy body that West and Gordon net, then drag behind the carriage before the dummy body explodes.
The Night of the Inferno - S1-E1
Revealing mistake: When Liddy's mansion explodes and burns, the switch from real house to cardboard model is very obvious. (00:35:15)
Revealing mistake: "Night of the Jack of Diamonds": During his fight with West, Sordo the bandito, who has a gray beard, is suddenly several years younger with a dark brown beard, thanks to the substitution of a stunt double. (00:35:30)
Revealing mistake: "Night of the Bubbling Death": Artemus takes off his coat and is wearing smoke canisters strapped to his back underneath. But the close fit of his jacket in previous shots reveals that the device wasn't there until just before he began removing the coat. (00:43:15)
Revealing mistake: "Night of the Underground Terror": During the climactic fight scene, James West's famously tight trousers rip apart in the crotch, amply revealing his very 20th-century white jockey briefs. A few shots later, that rip mends itself and the pants are split (much more decorously) down the right outer seam instead. (00:46:00)
The Night of the Skulls - S2-E13
Revealing mistake: In the livery stable fight scene between Gordon and Tigo, the tines of the pitchfork Tigo threatens Gordon with wobble, indicating they are made of rubber or a soft material and not metal.
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 Underground Terror - S3-E19
Revealing mistake: After West shoots Major Hazard on the water tower, the falling stuntman lands on a safety cushion that is about a half foot below the ground surface. Further, the next scene cut shows Major Hazard being covered by the tower contents, but Hazard is now lying on the ground surface, not below it like the stuntman.
The Night of the Vipers - S3-E18
Revealing mistake: The final gun battle in town has a gunman in a tower shooting at West. The gunman's perch is enclosed on all four sides by a bannister, but when West returns fire, shooting the gunman out of the tower, the bannister in front of the gunman has disappeared, allowing the stuntman a clear path to fall out of it.
The Night of the Vipers - S3-E18
Revealing mistake: After West shoots the gunman in the tower, the gunman launches himself clear of the tower, rather than merely collapsing and then falling.
The Night of the Legion of Death - S3-E12
Revealing mistake: The scar makeup on Montgomery's face begins peeling off as he is giving his speech.
The Night of the Bubbling Death - S3-E1
Revealing mistake: West and Gordon burn a perfect circle (unlikely in and of itself) in the metal floor in order to break into the dungeon below. West punches the circle out with his fist, then grasps what should be white-hot edges with his bare hands before jumping through the opening. Even if wood it would still be too hot to touch. (00:32:00)
The Night of the Big Blast - S2-E4
Revealing mistake: The "corpse" Miklos wheels into Dr. Faustina's laboratory is pretty healthy for a dead guy: you can see his chest moving up and down as he breathes. (00:27:00)
The Night of the Big Blast - S2-E4
Revealing mistake: During the sword fight on the stairs, Artemus' stunt double's face is in plain view in several shots. (00:30:00)