I figured the 70k number came from crime counts or something similar, since it's easy to build up non-negligible numbers pretty easily when 50 people are murdered in your country per day, which is the case in South Africa.
But individual crimes, even crimes partially or wholly racially motivated, do not make for a race war or genocide.
http://www.genocidewatch.org/southafrica.html
http://www.thetruthaboutsouthafrica.com/p/white-genocide-in-...