(at around 18 mins) Dingo's widow and Dooley are in front of the marshal's office and Marshal Ware hands Dooley Dingo's gun and personal effects. Dooley throws the gun and belt onto the ground and later he throws the five Double Eagles on the ground at the same spot. After they leave, Marshal Ware picks up the five coins, but the gun and belt are not on the ground and were never picked up.
When Dingo's effects are presented to the marshal in his office, the holster rig and pistol are completely different from the rig shown in the closeup at the beginning of the film as Dingo rides into town.
When bad guy Harley Baskam is preparing to face the marshal for the second time, from a rear view he has on both gloves, but when the camera cuts to his front, one glove is off his right hand.
The knife thrower who attempts to kill the sheriff tosses his knife with near-perfect accuracy (he missed) from roughly 50 feet away). However, not only is the knife not a throwing knife and thus almost certain to miss, the distance is simply too far for even the best of knife throwers to hit anything with any measure of success.
Randolph Scott's stunt double in the bar fight with Dooley has noticeably darker hair without a trace of the salt-and-pepper running throughout the star's hair.
In the opening scene, modern electric power poles are visible in the background.
The $100 dollars in gold that Dingo's brother throws away represented for many a year's salary. It's unlikely that he would have done so, even if he was ashamed of its origin because it is probable that he never would have seen that money in once place in his entire lifetime.
The men's shirts in the film button down the front their entire length. Shirts like this were not invented until the early 20th century, and did not become popular until the mid to late 1920s.
Several of the rifles in the sheriff's rifle rack are Winchester 1893 models. Since the film's setting is from the late 1870s until mid-1880s, those models would not have been invented, much less distributed.
The men's hairstyles are those of the 1950s when the film was made, rather than those of the 1870s/1880s when the film was set.
At the theater, the band plays an introduction with the conductor playing a violin while alternately using the bow as a baton. Near the end of the number, he plays the violin for three notes with no sound; then, he holds the bow as a baton and the three notes are played.