Did you try to refresh tab in browser during that bug?
So were you watching the game happening but weren’t playing? I feel like I’ve heard of a similar bug, like if two people match for the same game simultaneously. Was it auto match or a custom game?
Yeah, it happens every once in a blue moon. But the issue should be only cosmetic. Refreshing the page should show the correct players and the game should not be listed in your history nor contribute to your rank. At least I have not seen that happen anytime before.
I realised that it had no consequences (last screen shot), but just wanted to report it (as material when this - maybe - will be tackled by the developers of OGS).
Custom, not auto match.