Other mistake: Adam stops at the Wild Horse Saloon in a nearby town, seeking information about a man who he mistakenly thinks has killed Ben. Outside the saloon is a painted backdrop depicting some two-story buildings. It is the same backdrop seen from the saloon in Virginia City.
Other mistake: Ben and Little Joe do not see the horse belonging to Ben's brother Will, who is staying with the Cartwrights. Joe says, "I'll see if he's in his bedroom." Joe is out of the scene for only five seconds, then returns and says, "He's not there." Five seconds is not nearly enough time to go upstairs, check a bedroom and come back downstairs.