As the two boys ride away from the boarding house, the lady goes up to the steps in the shade. The next shot shows the boys farther away from the house which has the steps in full sunshine.
While not technically an error, the use of four separate levers and traps for the gallows was for dramatic effect and would not have been done if this was real. As seen in the quadruple executions of the Lincoln conspirators in 1865, the easiest way was to use one lever and one wide trap.
After Cahill catches onto his sons' involvement in the bank robbery, he and Lightfoot watch the boys as they're fishing. After the boys have traveled a while in the buckboard, the two men are seen watching the boys again from afar. The medium shot of Wayne and Brand shows that they're sitting on their horses in the very place from which they had been watching the boys fishing.
Many of the long shots of Cahill are obviously not John Wayne.
From Trivia: Most of the scenes showing John Wayne riding from a distance were filmed with Chuck Roberson substituting for Wayne.
From Trivia: Most of the scenes showing John Wayne riding from a distance were filmed with Chuck Roberson substituting for Wayne.
Rain falling at two different and constant angles when Billy Joe Cahill hides from Abe Fraser in the farmyard.
Lightfoot's horse has a saddle under the blanket. You can see stirrups hanging under the blanket and in a latter scene, Cahill uses them to mount Lightfoot's horse.
Half-Comanche scouts are allowed to put blankets over their saddles.
Half-Comanche scouts are allowed to put blankets over their saddles.
When Cahill first began to seriously suspect his sons were involved in the robbery he should have tried to force them to tell the truth about it.
Billy Joe says he is nearly 13, yet Danny obviously already knows his brother is only 11.
There is no explanation for why the two Cahill brothers have completely different accents.