When Richard Anderson is performing appendectomy surgery on Audra he is standing above her on the left side of the table. The appendix is on the right side of the human body.
Just before the horse and riders encounter the arriving train, the train is seen passing through a field: steel hydro towers are in the near background, and very obvious.
In the last few seconds of film, the 1870's train heads off into the background, and above is seen a full-width jet trail stream left from an airplane of 1966.