Revealing mistake: During John Elder's fight in Hasting's gun store, he ducks behind a counter, and as he pokes out his head, Hastings fires at him. On the counter, the "bullet hole" - containing the powder charge for imitating a bullet impact - is already visible before Hastings fires his gun.
Revealing mistake: When John Elder is at his parent's grave site and the sheriff comes up behind him, John Wayne has two guns to make it appear that he draws very fast. Both guns, the one in his hand and the one in his holster are briefly visible as he turns to aim the gun at the sheriff. Viewed on VHS.