Got AFK Leaverbuster for NOTHING?

So my last game (just won) got an score of about like 8/5/5 or 6 idk basically we won and i playd fair and respectfully blah blah we finish and out of nowhere i get message as if i left afk or smthn intentionally..?? And clearly i didn't (btw i just got of a 10 game chat restriction and 10min low queue for beign a little toxic but i stopped it) in this game i wasn't toxic at all i was quite respectfull and played from start to finish...So what happends? now