i find that highly unlikely. im sure Riot knows who is reporting you and if the same name comes up they probably look into much more closely. if your friend was reporting you, and you werent doing anything wrong, his reports would become invalid since he is abusing it. you stated yourself that you have been toxic before and thats probably your other teammates from different games. Remember that someone getting reported and actually getting ban/chat restriction is a timely process. You cant get ban from just one game unless something serious happen within that game, but even then its pretty rare.