What made the Oxford History of South Africa controversial, and what were the major criticisms of it by the radical historians?

What made the Oxford History of South Africa controversial, and what were the major criticisms of it by the radical historians? If the radicals had been asked to write, summarizing opening sentence for the "radical history" of South Africa, what would it say?

• Who were the "liberal" and "radical" historians? What did each group perceive to be the driving force in South African history?
• What events/writings/ideologies influenced their views?