As Artie examines the empty ledger books, from shot to shot the pages keep changing from tab-cut edges to straight edges and back.
The barroom fight is where Robert Conrad fell off the chandelier and got a serious concussion. This episode was originally for S3, but later completed for S4. At 8:35, the tables where West fell are gone/moved in the re-shoot when he gets up.
Desmond enters the hotel as West hides behind a door. In a mirror, one of Desmond's men sees West sneaking away. In the next shot, West comes again from behind the door.
Just before the Desmond and his men enter the hotel, Jim hides behind the open front door. As they start up the stairs Desmond checks his tie in a mirror. One of his men sees Jim in the reflection and Jim is shown bolting from behind the door. BUT when the camera goes to Jim directly, he is still behind the door. This view now shows Jim bolting from behind the door again.
From the opening scene James West is referred to as a "fed" by the sheriff and the saloon girl. The first recorded use of the slang term for a federal agent was not until 1915-1920 about 50yrs after the time period of the series.
Night scenes were filmed using a filter to darken the background. This resulted in night skies that are either blue or gray. But the night sky is black unless over a 20th/21st Century city lighted by electricity (which is NOT the case of 1870s America).
(at around 17 mins) West is lowering himself and Plank to the ground with his winch. Just after landing, the wire that helps suspend West is visible, attached to his back near his belt.
When Jim flees the hotel, he is hotly pursued by Desmond and his men. But as Desmond and his men leave the hotel they all duck behind something (such as the water troughs). They did this when all they could see of West was his back. They had NO reason to take shelter, and in ducking behind objects, they could only spoil their aim as they shot at West. Further, it was only after they were safely behind something that Jim turned to shoot at them. For all they knew Jim could have kept running and their ducking would have ended up hindering their pursuit.