In retrospect I should have saved a dump of my character after winning, but while I'm kinda sad about the non-recorded win (my second one, first one was with a character I started offline, so it was never registered), I just want someone to look into this since it's potentially a big problem.
People I spoke on the in-game chat then even remarked that when hovering over my name I showed as lvl 50, while the character link went to the apparently already lvl 45 character.
EDIT:
Same thing happened to this character.
Here is this character as it is now ingame:
