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 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.
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.
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 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 Miguelito's Revenge - S4-E12
Continuity mistake: As Jeremy Pike holds the glass of brandy, it changes position from being up to down, then up again.
The Night of the Returning Dead - S2-E5
Continuity mistake: In the barn, when Artemus jokes about "smoked ham," he and West are standing within inches of each other. Then the shot cuts to a wider angle, at which point they're several feet apart. (00:21:20)
The Night of the Big Blast - S2-E4
Continuity mistake: The large black straps hanging off the sides of Dr. Faustina's medical table disappear when West and Gordon burst into the lab. (00:44:00)
The Night of the Raven - S2-E3
Continuity mistake: West and Gordon are ordered to sit on the floor to talk to the diminutive Dr. Loveless at eye level. In all the two-shots, their shoulders are touching. In all the wider angles, they're sitting a foot apart. (00:09:05)