When Randolph Scott's character says goodbye to Mrs Greer at the end, he stands facing her with the horse on his left side. In the next shot, a closeup, the horse is on his right side.
The configuration of the mud changes on Gail Russell's face several times.
When Lee Marvin remarks that it looks like rain, there are clouds in the sky, but in the next cut to Scott and Russell the sky is clear and azure blue.
Gail Russell's dress has an obvious zip in the back of it, long before they were invented.