Your friend needs to learn to keep his hands off the keyboard. I saw a lot of provoking by team mates to him, and he hopped right into the hole with them. Game 1 was condescension and I probably wouldn't have punished for Game 2..Game 4, I ran across a real gem though.
Jax [00:00:59] get cancer and die slow f*gg**
Jax [00:01:16] you heard me *oc*sucker.
That would be why your friend is getting banned. Being bad at the game is not bannable, but I would have hit punish on Game 4 without even reading the rest of the chat for that game or any other game.