Quite right, he had that side, which makes his retreat from violence to negotiation and the fact that once in power he did not impose communism or even socialism on South Africa all the more remarkable.
A proper appraisal of Mandela cannot be secular hagiography, and should include mention of all the horrors he conscienced in his earlier career, but even actual saints sometimes showed their sanctity in being repentant sinners — St. Moses the Black has been a brigand and a murderer, St. Mary of Egypt had been a nymphomanical prostitute, and so forth. We are not to judge any man, so I cannot say whether in the proper sense — that he will stand at the right hand with the “sheep” at the Last Judgement — Mandela was a saint, but his change of tactics and the state of South Africa on the occasion of his death are good examples even to secularists of the power of repentance.
He’s on the same line with Bill Ayers in my book.. I’m sure most serial killers had a warm side at times as well but they are still killers.