The narrator consistently uses the American pronunciation of "Lieutenant" (loo-tenant instead of lef-tenant) throughout the film.
When firing their rifles, none of soldiers experience a recoil. This is most notable at 1 hr 8 secs when it shows Pvt. Eversmann repeatedly pulling the trigger, racking another round, and pulling the trigger again with no recoil.
At least some of the rifles carried by the British soldiers in this production were Lee-Enfield No.4s, which didn't enter service until 1940. They should have been SMLEs, later known as the Lee-Enfield No.1 MkIII.
The rank Brigadier and the insignia shown was not adopted by the British Army until the 1920s. The Brigadier General insignia was a crossed Sword and Baton in 1916.