MPs scoring. West leads the ace of spades, which is ruffed by south. A diamond is played to the ace and a heart to the king and ace, East pitching a club. West now leads a small spade to the jack which south ruffs again. South now cashes the king of diamonds, and then leads their spade. West wins and returns the jack of hearts, East throws another club and south wins the queen and cashes the 9 (East throwing another club). A club is now led which West ruffs and leads their final trump on which south discards a club. West now claims with 3 winning spades and south turned up with another trump. With the play going as it did, the contract ended up -2.
The handviewer doesn't handle revokes too well, but hopefully you can follow the play. Anyway, how do you rule?