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 Wolf - S2-E27
Factual error: Several airplane contrails are visible in the sky as West gallops his horse to Stefan's coronation.
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 Big Blast - S2-E4
Continuity mistake: Halfway between the opening credits and first freeze frame, Gordon and Ms. Lily Fortune are seen entering the private train car in the dark of night, but the shot before their entrance is of the front of the private train car at twilight. That shot of the train car also shows a backwards number 3.
The Night of the Janus - S4-E18
Continuity mistake: In the first boxcar scene, the train is shown standing among brown dirt and dead brush with the trees far off in the distant. When West opens the door to leave, there is a tree right in front of the door.
The Night of the Janus - S4-E18
Revealing mistake: About half way through this episode, the hooded man West is chasing goes through double doors and closes them. West slams his body to open the doors. He steps back to ram his body into the doors again to force them open. Before he does, we see the doors sort of slightly move back and forth (this looks very odd and unnatural) before West slams them open.
The Night of the Pelican - S4-E13
Revealing mistake: Towards the end of the episode when rocket one is fired, it launches very, very slowly with little force/velocity - obviously a prop.
The Night of Montezuma's Hordes - S3-E8
Continuity mistake: West has a different hairstyle as it is parted down the middle when he is fighting outside the Nugget Saloon. In the inside fight and throughout this episode, there is no part in his hair - with the only exception of this outside fight. (00:13:30)
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.