Don't understand Riot justice

Probably because private messages are opt-in.

Seriously, don't keep toxic people on your friend list. Super simple.

This is in a private message. You willingly accepted communication with this person by adding them.

KYS in pre game chat, in game chat, and post game chat are insta 2 week bans because it's on the zero tolerance policy list.

The best you can do is report that person using a support ticket and then block them.

In the future, don't accept friend requests from people who were toxic and hostile to you in a game as they usually have nothing positive to say to you in PM's.

How do you know they didn't get banned?

You don't have access to their account.

Because you actively had to accept him talking to you, so the punishment for him is MUCH lower than it otherwise would be.

Send in that screenshot to support and they might be able to do something about it. It's probably not going to be anything harsh because again, YOU accepted his friend request.

because copy pasting the code that is like "heres a report button" and the code that is "this here activates the bot to check over someones message" would be waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAY too much work for riot to copy paste. i mean dude cmon be real. if you are an asshole anywhere else, BESIDES ingame. who cares right? :D better keep pbe alive, an ENTIRE SERVER that riot basically does not care about. but implenting a report system in client? hell no man we cant do that, too expensive.

https://support.riotgames.com/hc/en-us/requests/new

You had the choice to not be exposed to his toxic behavior, but the other 4/9 members in your team/game didn't.