The Night of the Brain - S2-E21
Continuity mistake: When West and Gordon enter the print shop, they see Mr. Blackhurst's corpse sitting at his desk, with his head up, but when West and Gordon approach Blackhurst, his head is now noticeably bowed forward.
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 the Brain - S2-E21
Other mistake: Throughout this episode Gordon keeps producing orange-sized smoke bombs, but he has no pockets in his clothing large enough for all of them and if he did, the size of the bombs would be obvious in his clothing.
The Night of the Turncoat - S3-E13
Factual error: Artemus Gordon is standing in the train car throwing plastic darts. Plastic wasn't invented then, it would have been natural feather.
The Night of the Colonel's Ghost - S2-E24
Continuity mistake: The balcony railing is intact above the column post where West ties his horse. When West returns to his horse to leave, the railing post is detached and falling away from the balcony. (00:02:55 - 00:05:35)
The Night of the Surreal McCoy - S2-E23
Continuity mistake: When West is pulling the string to shoot the gun, we can see under both knees his pants are covered in dirt. As he runs to enter the Saloon, the front camera shot shows no sign of dirt. (00:44:10)
The Night of the Underground Terror - S3-E19
Factual error: The episode opens in New Orleans during Mardi Gras, circa approximately 1873. We hear a jazz band playing "When The Saints Go Marching In" although the song didn't emerge in a recognizable form until the end of the 19th century. (00:00:19)
The Night of the Turncoat - S3-E13
Visible crew/equipment: As West is swimming in the water tank that is filled with dangerous sea creatures (Hammerhead sharks, etc.) a modern day (1960's) frogman is swimming behind West in the tank.
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 Amnesiac - S3-E22
Continuity mistake: As Gordon interrogates Crotty, Crotty raises his cigar to his face twice.
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 Legion of Death - S3-E12
Continuity mistake: West and Gordon are being chased by members of the Legion, who wear green uniforms and black hats, but the stock footage of the chase shows the blue uniforms of regular U.S. Cavalry troopers.
The Night of the Legion of Death - S3-E12
Continuity mistake: The stock footage of West and Gordon being chased in the wagon by the Legion soldiers shows eight troopers, but other scenes show only four.
The Night of the Legion of Death - S3-E12
Continuity mistake: West sprinkles a thin line of powder into a circular shape surrounding him, but before the powder ignites and burns through the floor, it is thicker and has a wider circumference.
The Night of the Legion of Death - S3-E12
Continuity mistake: The stock footage of the wagon West is driving has a large opening in the front of the canopy as he is being chase down by the horsemen, but the close ups of West driving show a much smaller canopy on the wagon.
The Night of the Legion of Death - S3-E12
Continuity mistake: Stock footage of the wagon West drives to escape the horsemen shows a team of four horses, but the closer scenes show a team of only two horses pulling the wagon.