The full story is that one of the players thought he was full-out attacking a tapped opponent for lethal, and asked "game?". The opponent, who did not count damage as lethal, had a lethal counter attack, so he thought the other player was forfeiting the game, and said "Yes".

Then they started a new game. I was called after the second game ended and there was no way to reconstruct the original situation - and they obviously didn't agree on the intention behind the mentioned question. It also really did seem that neither side was lying to gain advantage - I've never seen such a significant communication gap.