Why is this such a hard thing to understand, he was contacted by Riot (after they updated their banning policies) and told he gets "Parole". By which they would aggressively monitor his play. He passed this period and was allowed back to play League of Legends once again.
http://na.lolesports.com/articles/competitive-policy-revision-permabanned-players
In addition, there was never any evidence of DDoS in his games. It was an unsubstantiated claim. Without proof, you are inherently innocent until proven guilty.
He has apparently changed and for that we can enjoy his mechanical plays.
Also this:
As far as I know, his absurdly high win ratio during the season 4 solo q season was due to his infamous DDOSing.
Is pure heresay. You have never played with him, and can only take the people who have played with him words on it.