In the beginning of the film, Jim Fallon appears in the window opening the divided curtain with both hands. Then the curtain on his right-hand side remains open while he holds the other part with his left hand. In the following shot from inside, the part on his right-hand side is closed.
In the saloon, Daisy dances around and returns to the stage with the help of two men who suspend her. Then we see a fat man standing on the stage corner, in front of a drink glass, clapping her. In the next shot he is drinking.
Walter 'Yukon' Burns has come from the Yukon gold rush, supposedly in Alaska. But the Yukon Gold Rush occurred in Canada, not Alaska.
Judging by the filming locations, the trees are coast redwoods (sequoia semerivirons). Giant sequoia are referenced in the writings on this film. Giant sequoia (sequoiadendron giganteum) are a different species located far away from these coastal filming locations in the Sierra Nevada Mountains.