Those settings looked so simple when I was typing them out..
The situation I had envisaged for a mischallenge was that the game would be voided as soon as the mistake was spotted and a new challenge issued. Any play on the mischallenge would be ignored. I hadn't counted on nobody noticing the mistake until the game was over, I was expecting a turn or two at most.
So, since I can't think of any option which is totally fair to everybody, I'm leaving you with a choice. Either both players can agree to void that game and play both halves from scratch on a new challenge, or you're stuck with the scores you got. The potential ten points you've both lost is the penalty for not paying attention.
Harsh, moi?










