Carsten I think you are perhaps missing the point. There cannot be any doubt that international business was omnipresent in Apartheid South Africa - and thankfully so because without foreign investment hundreds of thousands of jobs - on all levels, but mainly shop floor labourers - would have been lost and millions of people would have been forced into starvation. So yes internationally active companies such as UBS or Volkswagen, Mercedes, Siemens etc have been lobbying their respective governments and parliaments  not to disinvest from South Africa. And yes you are right they had a vested interest in doing so.
But to come back to this article; what does it tell us what we don't already know. And what is behind the headlines? Skeletons yes! Have we seen them before? Yes