The Night Dr. Loveless Died - S3-E4
Continuity mistake: In the opening scene, a cowboy sitting atop the balcony above Big Brad's Bar gets up and approaches the balcony's edge twice.
The Night of the Avaricious Actuary - S4-E11
Continuity mistake: The letter from the Cyclops Insurance Company that Gordon pulls out of his pocket is folded, wrinkled, and well-worn. In the close up of the same letter West reads, the letter is white, pristine, and not wrinkled or folded.
The Night of the Bubbling Death - S3-E1
Continuity mistake: When West breaks into the hacienda, the double windows he enters by have quite a bit of glowing light behind them. Yet when he climbs into the room, it's completely dark inside. (00:22:00)
The Night of Jack O'Diamonds - S3-E5
Continuity mistake: As West lowers himself down the face of the cliff with his hand-held rappelling tool, West does not have a safety harness attached until a few shots later, then the safety harness disappears.
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 Pistoleros - S4-E19
Continuity mistake: As West shoots it out with a bandito, the door jamb West uses for cover has a varying amount of bullet holes in it.
Continuity mistake: "Night of the Arrow": West and Gordon leave two champagne bottles and four glasses sitting on the table when they walk away to answer the door. When they return, the bottles and glasses have all completely changed positions by themselves. (00:41:30)
Continuity mistake: "Night of the Arrow": President Grant's cigar keeps getting longer, shorter, and longer again as he gives West and Gordon their special assignment aboard the train. (00:08:10)
Continuity mistake: "Night of the Bubbling Death": When Grigsby first approaches the stolen U.S. Constitution, it's under glass (we can see the light reflections). But seconds later he lifts the paper without removing the glass, which has disappeared. It's back later, when West must cut it to retrieve the document. (00:09:10 - 00:36:30)
The Night of Miguelito's Revenge - S4-E12
Continuity mistake: The barber chair West sits in has dark wood arm rests, yet the close up of his hand as he is being chloroformed by Loveless shows white arm rests.
The Night of the Howling Light - S1-E14
Continuity mistake: It's night outside the train's windows - until Artemus looks out at the attacking Indians; then it's day, and in next shot, it's night again. (00:06:55)
The Night of the Howling Light - S1-E14
Continuity mistake: Akima dies with his head tilted to the left. In the next shot, he's managed, even though he's "departed," to tilt his head to the right instead. (00:49:20)
Continuity mistake: "Night of the Arrow": When Artemus pours the president a drink, the glass is only 1/4 full. When Grant picks it up, however, it's suddenly 3/4 full. (00:09:15)
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 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.
The Night of the Legion of Death - S3-E12
Continuity mistake: The long shots of the wagon West is driving shows it being chased by the horsemen in moonlight, lighting up the terrain showing trees, rocks, and scrub, but the close up of West driving shows nothing but blackness in the background.