I agree that stuff like this needs to be well-sourced, but I'm glad to see some of it getting attention. Mandela is, and rightfully so, held up as a beacon of kindness and forgiveness that we should all try to incorporate. But I think we do his legacy a disservice by not talking about all the corruption he fought, and who we really was (including the parts that make him look like, as you suggest, he "pretty much deserved to go to jail").

I've done a lot of reading on this topic myself. I would love to post some sources but I don't have my books with me at the moment. But for what it's worth (which is not much, admittedly) - let me add my endorsement as a fellow HNer that what the author talks about is plausible, and there is plenty of evidence if you care to go looking for it. I believe this is a well-accepted theory by many other South Africans, rather than a fringe conspiracy. But yes - unfortunate that the author doesn't do more to back up the claims in a verifiable way.

edit: The cover is different, but I'm pretty sure this is the book I read that did the most to back up these events: http://www.amazon.com/Inside-B-O-S-S-Africas-Secret-Police/d.... The details, as I remember them, have always been very consistently reported by the various "sources".