Found a boosted player, but not sure who has boosted them.

Normally I would not have gone into chasing after this nor do I want to make this a witch hunt but after playing a single game with this person, they had tended to afk and just sit in the nexus and troll for simply not being given a buff even though they weren't doing well themselves. After the game I decided to look and see just what level he was and his match history which is currently full on pantheon and Annie both chars they had never played in Ranked whatsoever. I knew I had to check lolking and in the second picture it shows the elo jump which seems to take place in less than a week. Finally to wrap this up I also added him after the game, no dice on making a D5 friend.