Continuity mistake: Colour Sergeant Williams and Private Storey are miscredited as "Company Sergeant Major Williams" and "Corporal Storey." Neither is promoted over the course of the film, and both are not only addressed as "Colour Sergeant" and "Private," respectively, but also bear the rank insignia of a Colour Sergeant and a Private, respectively.
Continuity mistake: Just before Sergeant Williams' company retreats in disorder, they give the Zulus one final volley but some of the Zulu bodies are right up to the soldiers. How did those Zulus get right up to the British line without being hit earlier?
