The Man Who Broke the Bank at Red Gap - S2-E17
Factual error: An egotistical, prissy and dishonest lawyer like Mr. Fletcher wouldn't make the mistake of allowing his name to be misspelled on his office door. It reads "Winfred Fletcher." His first name, as it's pronounced throughout the episode, is "Winford." (00:26:50)
Shootout at Diablo Station - S2-E11
Plot hole: Well within earshot of the others in the small room, Curry comments to Heyes (purely for the viewers' benefit, since Heyes already knows it) that if Lom Trevors is killed, their amnesty will go with him. This information should have blown their cover, but for some strange (and unbelievable) reason, no one wonders what he's talking about. (00:19:00)
Six Strangers at Apache Springs - S2-E7
Continuity mistake: Heyes' horse is shot out from under him by the Chiracahua, forcing him to leave it behind and ride double with Curry. But when they return to Apache Springs, Heyes is again riding the same horse that was shot earlier. (00:40:40 - 00:43:30)
Dreadful Sorry, Clementine - S2-E10
Factual error: Heyes burns the photo - but he shouldn't have been able to. In the 1880s, it should be printed on tin and not on paper. (00:11:00)
Shootout at Diablo Station - S2-E11
Continuity mistake: Gorman's left hand is in two places at once during the card game. We see it resting on his thigh under the table. One shot later, without time for him to move, both his hands are holding his cards. (00:19:30)
Shootout at Diablo Station - S2-E11
Continuity mistake: The stage driver's hat is white when they leave town, black during the trip, and white again when they arrive at the station. (00:02:00 - 00:05:15)
The Reformation of Harry Briscoe - S2-E9
Continuity mistake: Molly's hands are tied with leather straps. But when Briscoe and Sam barge into the campsite, she pulls off her blanket and stands up with her hands free. A moment later, she once again has the leather straps binding her wrists. (00:30:15)
Six Strangers at Apache Springs - S2-E7
Revealing mistake: During the saloon brawl, recycled footage causes Curry to change into his first season hat for a few shots. After the fight, he has his second season hat back on. (00:28:00)
The Men That Corrupted Hadleyburg - S2-E18
Audio problem: Final sound edits were incomplete on this episode when star Pete Duel committed suicide, so his dialogue is "looped" by another actor in several places. Though it's an excellent imitation, it is most noticeably not Duel's voice when Heyes and Curry are waiting for Harry in the opening scene, at the campfire with the Tapscotts, and when Harry tells them about the trial's outcome.
The Posse That Wouldn't Quit - S2-E5
Revealing mistake: All the shots of the pursuing posse are "borrowed" footage, which might never have been obvious - except for the fact that one shot shows us a recognizable Heath and Nick Barkley from "The Big Valley" at the head of the pack. (00:17:00)
Continuity mistake: While Curry and Heyes are panning for gold, the same shot of someone's bare arm and shoulder above the gold pan is inserted several times. But neither Heyes nor Curry is shirtless, and no one else is with them. (00:11:05)
Shootout at Diablo Station - S2-E11
Continuity mistake: The stagecoach station during the day and what is supposedly the same station after night are shots of two completely different buildings. The night shot is stock footage of a different set. (00:19:10 - 00:35:00)
Six Strangers at Apache Springs - S2-E7
Continuity mistake: In memory of their friend Seth, who died in "Smiler with a Gun," Curry grew a mustache that he kept for several months. (As a running joke, Heyes kept prodding him to get rid of it and Curry kept refusing.) Because production and air dates differed, the mustache is, without explanation, missing here. It's back in the next episode, gone again in the next, and reappears for the last time in the next, where Curry finally shaves it off.
Shootout at Diablo Station - S2-E11
Continuity mistake: Four horses pull the stagecoach. In long shots, the left lead horse has white fetlocks. A moment later, when the coach pulls into the station, the white-legged horse has moved to the leading right position. (00:05:00)
Six Strangers at Apache Springs - S2-E7
Continuity mistake: During the dinner, Grace is in two places at once in the background. She's at the far right end of the bar drying a glass when the camera is on Mr. Fielding. When the camera reverses angles to show Mrs. Fielding, Grace has instantly jumped to a spot at the far left end of the bar, and is still drying the same glass. (00:12:15)
Revealing mistake: The night scenes around the campfire are plainly shot on an indoor set and not outdoors. Phony exteriors were seldom used on this series, but L.A. had suffered a record five inches of rain that forced the crew to either shoot indoors or fall behind schedule.
Shootout at Diablo Station - S2-E11
Continuity mistake: In the interior shot, Hayfoot walks out the door with the flag under his right arm. He then immediately emerges in the exterior shot with the flag under his left arm. (00:37:30)
The Man Who Broke the Bank at Red Gap - S2-E17
Continuity mistake: Heyes and Curry are waiting at the granary at 10 p.m. at night when they hear the posse approaching. In the next two shots of the riders coming over the hill, they're under a blue sky in full daylight. (00:15:05)
Six Strangers at Apache Springs - S2-E7
Continuity mistake: Despite the episode title, there are only five strangers in this story. Even if you counted Caroline and Smithers, who live there and so aren't among the strangers, they'd make the total seven.
Audio problem: Just before Curry shoots the rattlesnake, Heyes says, "Don't anybody move." But his lips don't move when he says this. (00:11:20)