Stephen Biko was. I'm not defending Mandela and the ANC, but by that same token the actions and abuses of the NP during apartheid should not be lightly dismissed either.
Since you know the name of this ‘Steven Biko’, I’m certain you also know the names of all those murdered by Mandela’s comrades, then and later, or else ask yourself how come one and not the other, and also who and why drilled the name ‘Steven Biko’ into your memory.
Biko was a good man.