After the two horses that were blindfolded and forced to go over a cliff were killed, a new rule was enforced and later endorsed by The Humane Society of America in which strict standards were created to protect Animal Actors in which at the end of the movie and added to the credits listed as "No Animals Were Harmed or Injured in the Production of this Film...". Now all films involving any Animal Actors must have present a member representing The Humane Society of America to insure that all animals are treated humanly and given a safe environment in which to work.
While shooting his role in the Ozarks, Lon Chaney Jr. fell off his horse during a chase and was trampled by the horse behind him. He was not injured badly - he managed to finish his scenes that day. But director Henry King, blaming Chaney's nightly drinking for the mishap, fired him, and he was dropped by his studio (20th Century Fox.)
After they get Jesse out of jail, in the head-on shot of Frank and Jesse riding while being chased by the posse, road dust from the camera truck is visible ahead of them.
On the river bank, when Jesse James bids farewell to Pinkie, the latter changes place, from beside the mule, with his hand on its back, to the front of the mule, holding the rein, between shots.
On two occasions the newspaper editor dictates his editorials directly to the typesetter. Such a rapid realization of spoken word to printing block, without the medium of a written dictation, is impossible.