Mandela had long been in prison by the time of the lethal attacks listed on that page. As far as I'm aware all the bombings he organized resulted in no casualties, which is why he wasn't charged with murder during his trial.
They did indeed seem to all be non-lethal forms of sabotage, with the worst atrocities being done by his wife Winnie Mandela. However, he was the one to order the shell house massacre when he was president; there is blood on his hands.
Frustratingly I was saying the exact opposite.
It is quite unfortunate how arguing about something will invariably lend you to seem in favour of it.
In regards to Gandhi, his racism towards black South Africans was one of the views I was talking about him reconciling; he originally supported a white minority rule of South Africa and of course didn't hold that view for much longer. I'm unsure as to what changed on his views towards women, if they changed at all, so you do present a convincing point there at least.
I suppose in the end it all boils down to what each figure symbolizes. Individually no one person is a paragon, yet if they become a symbol for the fight against some oppressive power like Apartheid or a fight for civil rights, we will be loathe to remember their flaws till they become the mythical paragon.