Right after falling into the river Inger Stevens looks completely dry (at about the 29 minute mark).
When Emily tries to escape horseback, and hits Capt Bentley with a sword, the blade can be seen bending and flopping.
In the "night" escape scenes, the sky is shown as blue and white clouds are visible indicating it was shot during the day using a filter to make it appear as night.
Early on, the Union and Confederate troopers are armed with single shot breech loading carbines, but in the final battle scene, all of a sudden, everyone is armed with Winchester repeating rifles that do not exist in 1865.
Before the missionary wagon comes to the river just as the wagon passes the camera there is a yellow and white umbrella visible in the near distance. It appears to be an area for the film crew to rest. Between the 28th and 29th minutes.