I was banned, yet he wasn't?

I understand why I was banned. I don't think it's justified, but I understand why you do and I can accept that and learn from my mistakes. However. The heimerdinger I was referring to in these chat logs (not shown in the image but I assume you have access to the logs) said the exact same things to me throughout the game and called me out for intentionally feeding. I am unsure why I was punished so harshly yet he was (to my knowledge) left untouched. I feel that this is very hypocritical and unfair towards me. I'm not asking you to revoke the temporary ban (I doubt that is even possible) but I ask you this: Why is it that when two people are doing the exact same thing, only one of them gets banned?