I've actually had this happen in an exhibition game. Some dude playing Jago beat me and then I re-matched him and had him into his second life bar with me in the 1st. All of a sudden it said opponent has left the lobby. So I queued up for another match. The guy messaged me and wanted to know, why a F2P Jago player got a supreme victory on a paying player (I was Sadira). My reply was more like, why did you rage quit when I had you into the second health bar. He said I ultra'ed you and won, go watch your playback. I then realized we desynched and I replied to him and said I think this is a misunderstanding and the game desycnhed on us. You left the game on my screen and you won on yours. Neither of us did anything wrong.