One of the soldiers is singing the folk song Denver, which was written by Randy Sparks for the New Christy Minstrels in 1962. The movie is set during the Mexican Wars of 1916. How a song written in 1962 was sung in a movie made in 1959 is a complete mystery.
Major Thorn improperly salutes Colonel DeRose in the opening scene when he is dismissed. He should have saluted and held his salute until it was acknowledged. Instead, he lowers his arm even before Colonel Rose acknowledges it.