Other mistake: Handsome and Charming head out of Snakes End (followed by the newlyweds) and begin their long journey. It then cuts to Cactus Jack before he begins the journey, and at the start of this shot as he places Whiskey's bit, we can see the signpost with three wooden arrow signs and the hillside behind him. This is the same location where Cactus Jack lays trap number seven, named "the tunnel in the hillside," on the next day during the journey; noticeable when Handsome and Charming arrive. (00:28:35 - 00:54:45)
Audio problem: The Rabbi's horse is bucking in reaction to the rattlesnake, and all the while the Rabbi is yelling in Yiddish - but his mouth is not moving.
Factual error: The action in this movie takes place in 1869, yet half of the handguns are 1873 Colt Peacemakers, and the remainder that are Army or Navy Colts are all cartridge conversions, which were not available until 1871.