One of the repairmen on the Silver Streak (Higgins) tosses away a cigarette that he was holding in a wrench, but in the very next instant he has another fully lit cigarette.
On the cable lift on Hoover Dam, the amount of people on the lift alternates between four and six, even when it's in the air.
The claim is made the iron lung can't be carried on an airplane because it's too heavy, but 5 men are able to push it off the loading dock onto the train. However, they are shipping seven iron lungs to the dam site and each weigh about 750 pounds. No single aircraft of that time could have carried that weight and volume.
Interior shots of Tom at the throttle show the controls near the center of the cab but the exterior views show the real engineer at the window sometimes with his arm resting on the window sill. Tom couldn't even reach the window from his position.
When the train crosses the swinging bridge that closes just in time, the clouds in the background change slightly, indicating an edit was made to make it appear the bridge closed just in the nick of time.
When Captain Bronte is behind lead away by Veschensko, a moving shadow of a large studio light is visible on the shops alongside them.