Revealing mistake: When Mr Witt rides out of the Zulu camp in a 2 horse cart at the beginning of the movie, just before it exits, you can see it's a stunt double at the reins.
Revealing mistake: During the first major Zulu attack, a warrior leaps down from the rampart and faces a British soldier (near the bottom right of the screen). The soldier lunges with his rifle and it's all too visible that his bayonet stabs to the side of the Zulu's chest.
Revealing mistake: In the scene where the cavalry arrive (Chard thinks they are coming to help) and ride up to the sandbag wall, you can quite see the lighting being turned on as they get near. For a few seconds they are all in heavy shadow under their hat brims, then suddenly their faces are well lit. It's not a cut, it's one continuous shot.