On one of the battle scenes, the Zulus are charging towards the camera. In full battle dress, spears, shields etc etc. And at least 3 Zulus have digital wrist watches, very tribal.
Apparently wristwatches were given to the extras as gifts/payment, and some of the guys wore them deliberately for a bit of mischief. I've done a bit of extra work and we often try to sneak in funny faces or winks towards camera, or changing something about our costumes to see if it can get shown