During the battle between the army (driving herd of horses) and the rebels, Pete Elm's face is dirty/clean/dirty between shots.
When attempting to drive out the horse thieves by burning them out, the wagon section that Kearney drove is twice pushed over the edge in flames.
After having escaped from the military prison with two of the horse rustlers Kearney rides back into town with McCool he has had an empty holster the entire time. After dismounting in the corral he walks into town and has a revolver in his holster.
During the "hat on a stick trick" scene, the sunlight and shadows on Kearney are inconsistent.
When Captain Tennick is trying to line up a shot at the leader of the horse raiders, his kerchief changes from a bright red plaid color to that of an off-white, then back and forth several times.
At the beginning, General Halleck is wearing a crimson sash. As a General, he should be wearing a cream-colored sash.
There were never any Confederate units in Colorado during the Civil War.
At 45 minutes into the film Maj. Kearny describes the raiders as"one-third Confederate regulars and the rest a bunch of Jayhawkers. " Jayhawkers were Union militia from Kansas, not rebels. The correct term would have been "bushwhackers".
Lt. Col. Hudson wears a junior officer's coat with a single row of buttons, instead of a double row, and has red shoulder straps of artillery, instead of yellow, as a cavalry officer should wear.
When the jail break occurs it is nighttime but by the time they reach the horses it is day time. No attempt was made to use a day-for-night filter.
The Trapdoor Springfield rifle featured in this movie was issued in 1873. Its immediate breechloading predecessor in the military was not produced until after the Civil War.
Set during the Civil War (1861-1865), yet at least one character appears to have an 1873 Colt Army revolver.
When Kearney and the troopers ride out of town in the wagon with the Springfield rifles, at one point the edge of an automobile road can be seen in the lower left of the screen.
As they are unstrapping the rifles from the wagon section before attacking the raiders, Major Kearney says, "Sgt. Snow, Lieutenant, come with me." Then his mouth keeps moving but no dialog is heard.
In the mirror flashing scenes, Major Kearney tells the riders to hold their mirror steady for 30 seconds if everything is okay but flash it around if there are any problems and they'll wait to move the horses. In the next scene, the mirror can be seen flashing from the top of the ridge meaning there was a problem but the whole camp gets excited and moves out with the horses.