Revealing mistake: Sam, the third victim, is shot and killed while driving his wagon out of town. We see a long shot of him riding away, then we hear the rifle firing. But the camera lingers a bit too long after that - just enough for us to see the wagon continuing on its way, with a perfectly healthy Sam still at the reins. (00:16:40)
Continuity mistake: When they've opened the chest, Leslie pays Heyes $1500 in cash, which he's holding in his hand when the gang of robbers gallops up. In the next shot, Heyes turns and raises his hands, and the cash he was holding has disappeared. (00:31:40)
The Man Who Murdered Himself - S1-E10
Revealing mistake: At the beginning of his trip with the TNT wagon, Curry is seen driving with a hill in the background and a road winding past rocks and green grass. Several miles into the trip, he's coaxing the team over a ridge, and when we cut to a close-up, the same road is behind him. It's the same shot, recycled from earlier in the episode. (00:06:15 - 00:15:45)
Continuity mistake: Having borrowed the valuable uncut stones from Soapy, Heyes and Curry don't seem able to keep a very good accounting of them. Ten are sent out for evaluation, and twenty-one more are used to salt the fake diamond field. They should be returning thirty-one nuggets to Soapy at the end of the con game. Yet there are fewer than twenty diamonds on the table when Soapy empties the cloth bag. (00:49:50)
Return to Devil's Hole - S1-E7
Continuity mistake: Heyes takes Clara's handbag and dumps its contents on the table. A bundled stack of bills at least an inch thick falls out. Several shots later, though, the pile of money is much thinner, about half its original size. (00:08:25 - 00:10:10)
Never Trust an Honest Man - S1-E14
Factual error: For a man of the cloth, the Preacher is remarkably ignorant of one of the best-known passages of the Bible. He says that the 6th Commandment is "thou shalt not steal" and the 8th "thou shalt not kill." It's the other way around.
The Legacy of Charlie O'Rourke - S1-E15
Continuity mistake: While Heyes and Curry talk to Charlie in his cell, Curry's hands change positions on the bars every time the camera angle reverses. (00:04:45)
Continuity mistake: The rifle Curry slings to his saddle when he sets off after Jake disappears during his journey, then reappears just in time for him to use it in getting the drop on Jake. (00:42:40 - 00:44:25)
Continuity mistake: During the scene in the gentleman's club, Grace makes an instant costume change. When she's inside the club room, she has on a white lace dress and hat. When she and Heyes walk the drunk Sylvester out into the hall, she's wearing a bright red dress instead. (00:12:30 - 00:13:20)
Continuity mistake: When the bad guys rough up Heyes, his hair is disarrayed. But when the shot cuts, it's neatly combed again. (00:13:00)
Don't Get Mad, Get Even - S2-E21
Factual error: A grumpy Heyes tells Georgette and Curry that he's been sleeping in a stable loft for two days without a bath or a shave. But he's completely clean-shaven: not even a hint of stubble showing. (00:15:00)
Suggested correction: He is not "completely clean-shaven." He has evident facial hair.
Visible crew/equipment: When the sheriff and his deputy knock on Rachel's door and she opens it, the glass shows us a studio reflector and some of the camera crew. (00:39:30)
The Legacy of Charlie O'Rourke - S1-E15
Factual error: When Alice, Heyes and Curry dig up the gold bars, they realistically have to use both hands to lift each one. But Heyes then fills two cloth bags with six bars each, hefts the sacks easily and slings them over his saddle. Conservatively, each of those bags would weigh 180 lbs. - he's just tossed the equivalent weight of two full-grown men over his shoulder onto the horse.
Continuity mistake: When Heyes and Curry, on horseback, are arguing with Joe, the rifle in Joe's hand shifts orientation each time the camera angle reverses. It's pointing up, then down, then up again. (00:38:00)
Continuity mistake: In the opening scenes of the chase, Heyes is wearing a vest, then not wearing a vest, then wearing a vest.
Which Way to the OK Corral? - S2-E20
Other mistake: When Neville Brand is listed as a guest star, guest star is misspelled as "Guast Star." (00:05:08)
Wrong Train to Brimstone - S1-E4
Factual error: This entire episode takes place in Wyoming, because of the Bannerman plot to ambush the Devil's Hole gang, but a sign at the train station where Heyes and Curry board states the elevation as 2315 feet. No location in Wyoming or northern Colorado is that low. One would have to be in California, Texas, or eastern Kansas or Nebraska. (00:04:05)
The Men That Corrupted Hadleyburg - S2-E18
Factual error: Heyes and Curry are reading the Denver Post in the beginning scene, but the Denver Post was not published under that name until 1901, nor published under its earlier name, The Evening Post, until 1893.
Never Trust an Honest Man - S1-E14
Character mistake: When Heyes and Curry join the poker game with Harlenjen near the start of the episode, Harlenjen says, "Heyes bets," even though it looks like the other guy is betting first, plus he doesn't know Heyes' real name.
Suggested correction: He said "Ace bets", meaning the high card showing on the table places the first bet. The guy replied "Ace bets a hundred."