In the movie the soldiers are taught to fire the Lee-Enfield rifle using their index finger on the trigger. This is incorrect. Guards regiments in the early part of the war were taught to fire 20 aimed rounds per minute. This fast rate of fire was achieved by virtue of the close proximity of the bolt mechanism and the trigger mechanism on the .303 Short Magazine Lee-Enfield rifle. Soldiers in Guards regiments were trained (like the Old Contemptibles) to fire the Lee-Enfield using the middle finger to fire the weapon while the index finger and thumb worked the bolt. The index finger and thumb would keep hold of the bolt THROUGHOUT the firing procedure, thus speeding up the rate of fire considerably. In the movie soldiers are clearly shown releasing the bolt on every shot in order to use the index finger to fire the weapon.
Many of the photos of wounded men that the Kipling family search through clearly show a WW2 pattern 'Brodie' steel helmet. Not only is a WW2 steel helmet wrong, ANY steel helmet is wrong for late 1915 as steel helmets weren't issued to British troops until 1916.
In the movie Jack Kipling is shown wearing an officer's tunic with rank pips on the shoulders and with no rank markings on the lower sleeves. This is incorrect for 1915. Until 1917 officer rank was always displayed on the lower sleeves.
Speaking in front of a famous recruiting poster of Lord Kitchener, Rudyard Kipling announces the outbreak of war (beginning of August, 1914). The poster of Kitchener was first published in September 1914 in the journal 'London Opinion'.
Rudyard Kipling was a great flag waver (read his poem: 'The English Flag') yet in the scene where he announces the outbreak of WW1, the Great War, we see the Union Flag, on the podium in front of him, upside down, while all the others are correct.