Wow, most toxic player ever

Now I know some people can be pretty toxic but I just had a game with the most toxic player in League of Legends. Why do I say this? The player ragequit/sat on fountain at level 4 we continued to play 4v5 and were winning. At the end of the game we won 4v5. We knew this player was still in game because he would continue to rant about how our jungler stole his CS in early game and would buy items as we continued to take objective after objective. This isn't the rarest form of toxic player I know so you may be asking why was he the most toxic ever? because we were kind to him the entire time. The jungler apologized and explained he was afraid the CS would be lost before the he got back to lane. (this was only 8-10 cs mind you and the toxic had just died) We didn't berate the player or even call him toxic for the majority of the game. We asked him to help out and players kept offering him side lane waves to catch up in CS. We were up 5 towers, 3 dragons, made a baron play and got baron and still the player continued to rant about the 12 cs from the beginning of the game.

If I ever become so petty and selfish that I try to ruin the game for 4 obviously nice people I hope I get banned forever from LOL.