So its toxic to call someone out for eloboosting?

So I was playing on a silver smurf and I had this phenomenal teammate who seemed a little... lost with the game. He did a grand total of 10k damage as toplane in a 40 minute game and was always alone doing his own thing while the rest of us grouped. His overall cluelessness eventually caused us to lose the game. I decided to lolking him up when I was dead and it turns out he went 10/10 in placement matches recently then and lost every single game after that. So after the game I called him out on his obvious elo boosting and I was hit with the "Your recent behavior is not in line with the summoner's code yada yada...etc." warning. What am I supposed to do? Honor him for good teamwork and keep pretending players like this earned their spot on the ladder fair and square? Players like him that keep buying eloboosting services ruin the ranked experience for everyone.