Alright so let's say a new player just joined a game and then went to queue for Blind Pick Summoner's Rift, he couldn't get a kill and has died around 8 times in the last 10 minutes of the game, his teammates start flaming him for being a troll and threaten him with a report for trolling. Afterwards, the new player has found out how to chat, and he said for them to shut up and not to be toxic, then the flamers start giving very strong insults (family insults, dead loved ones etc), the new player has said that they are losers and that they will be muted. They were muted and he will report them all after the game. After the game finished, the new player has reported them and his 4 teammates also reported him.
2 days later the new player gets perm ban for having a negative attitude, and the flamers were clean without a ban.
So my question is, why is riot letting the flamers trash talk, give strong insults and accuse noobs of trolling do all of that without a ban?