Well, its possible that more than 1 guy use that nick that would explain a lot.
Or server duplicate but i checked and its not the case.
You can switch colors during the game, it doesnt change anything , except if you have colors code set , if you switch too early you dont have more than 2/3 session played with the right colors.

But indeed thats weird ... dont know cant really say , maybe a big or ...

But when the guy appears 2 times on the same session, check pings you will see its not the same and could explain my first suggestion.
maybe im wrong and its a bug ..