Alias Smith and Jones (90 min.) - S1-E1
Revealing mistake: The electric light bulb in Lom Trevors' lamp is visible. In one shot, you can even see the filament wires. (00:18:15)
Revealing mistake: At Armandariz's hacienda, a power cord is peeking out from behind the large chest against the wall in the main room. (00:18:00)
Never Trust an Honest Man - S1-E14
Revealing mistake: At the end, when Christine's father enters the kitchen, the unmistakable outline of a papered-over electrical outlet is showing on the wall behind him. (00:45:10)
Revealing mistake: During the stage hold-up, there are several bright white 20th Century buildings visible in the distance behind Weaver. (00:09:25)
The Legacy of Charlie O'Rourke - S1-E15
Revealing mistake: Alice is supposedly playing the guitar while she sings to Charlie in the jail cell. But while her fingers are moving, they aren't forming proper chords on the instrument's strings, nor does her strumming match the music we hear. (00:17:00)
Never Trust an Honest Man - S1-E14
Revealing mistake: In one of the early panoramic shots of the train heading toward the mountains, there are two jet contrails in the sky at the upper right of the screen. (00:07:00)
The Legacy of Charlie O'Rourke - S1-E15
Revealing mistake: When Heyes and Curry send the empty stagecoach off to mislead the posse, the road has several 20th Century tire tracks running across it. (00:29:00)
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)
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)