Corrected entry: British non-commissioned officers are never addressed as "Sir."
Corrected entry: In the movie a lot is made of the unwillingness of the Quartermaster to issue ammunition and of the difficulty in opening the ammunition boxes. In fact the boxes could easily be kicked open or smashed open with a rifle butt and shortage of ammunition was not a major factor in the defeat. The Martini Henri rifles had a tendency to overheat and jam and this was much more problematic to the British. After the battle, many unworkable rifles were found abandoned.
Corrected entry: Whoever did the costumes had no idea of British Army officer badges of rank. Junior officers, LTs, display a crown, the badge of a major. Lt. Col. Pulliene shows 1 'pip', the rank of 2nd Lieutenant. Chelmsford has sword crossed with scabbard plus two pips - no such rank: a Lt. Gen. has sword/scabbard plus a crown. Lt. Col. Durnford is correct: pip surmounted by a crown. But Durnford I think, was actually a full colonel: 2 pips in line surmounted by a crown.