Alias Smith and Jones (90 min.) - S1-E1
Factual error: Kyle strikes a match on the wooden floor to light the dynamite's fuse. In the early 1880s (the era in which this series is set), a portable flint-and-tinder kit was the common method of sparking a light. While "strike anywhere" matches had been invented by this time and were quite the rage in Europe (despite an alarming tendency to explode due to the volatile chemicals used), they were an unknown commodity on the American frontier until well after the turn of the century. (00:03:00)
Alias Smith and Jones (90 min.) - S1-E1
Factual error: The telegram delivered to the sheriff's office is in an envelope with a machine-cut, transparent cellophane address window. This type of envelope wasn't manufactured until well into the 20th Century. (00:58:15)
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)
Wrong Train to Brimstone - S1-E4
Factual error: When the train is fully boarded, the conductor waves a lamp to signal the engineer. It's supposed to be 8 pm at night, but it's suspiciously sunny on the platform - and the signal lamp is noticeably not lit. (00:08:45)
Factual error: The dresser mirror in the saloon girl's boudoir is ringed with photos - but they're 20th Century color Polaroids. (00:24:00)
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
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.