Plot hole: The judge asks Jed Cooper if he would like to see what McCloud looks like, (McCloud is the killer who cheated him and murdered the rancher), as he is being hanged. Of course since Jed Cooper had previously purchased the cattle from McCloud, he knew what he looked like. (00:10:00 - 00:15:00)
Factual error: In the scene where people are arriving in town for the hanging, a family are told they have tents set up in the Boondocks. "Boondocks" is a Philippino word that entered the English language when the Philippines was a colony of the U.S. The movie is set 9 years before the Spanish American war so the word didn't exist in the English Language during the period of the movie. (01:11:20)
Other mistake: At the beginning when the lawman is cutting down Eastwood from tree in the background you can see a white vehicle driving along a road in the background.
Continuity mistake: At the beginning, Eastwood dismounts from his horse to rescue the calf lying in the river. His horse is left standing in the river with the water up to his knees. When Eastwood places the calf on dry land, his horse is standing nearby. The horse's legs are dry.
Visible crew/equipment: In the scene where the judge is releasing Clint Eastwood and telling him that his story checks out he calls him over to the window to watch a hanging. As the guards walk down the scaffold steps on the ground under the gallows there is a pile of rope and next to the rope is a modern electrical box of some type. It's silver with with louvers (vents) in it.
Continuity mistake: During the opening credits, when titles are appearing under Eastwood's swinging feet, you'll see the footage of the swinging feet reverse itself at least twice.
Factual error: Near the end, when Cooper and Rachel are talking in the street, you can see in the background a multi-story brick and glass office building. It appears again a few shots later.
Revealing mistake: Towards the end of the credits, on the highest mountain peak, you will see an air traffic light flash twice.
Factual error: As the hanging begins a lady is walking across the street, she is wearing modern tennis shoes.
Continuity mistake: When the blacksmith looks up and recognises Jed, he is standing in front of the fire ready to put the horseshoe in. After Jed dismounts and the camera cuts back, the blacksmith is standing a few feet to the right of the fire.
Factual error: The film is set in 1889 yet there's a sign for Kitchen Queen Baking Powder in the store window, which didn't exist until 1898.
Factual error: When the camera pans above the gallows prior to the hanging, modern high tension electrical lines are visible through the trees in the far background.