I was West and North was in 5♣X here, after my partner and I had bid both majors: pairs MPs, Game all dealer W:
As things stand 5♣X is an excellent sacrifice at game all, because I can't see how E-W can come to more than 4 tricks in the normal course of play - and there's a certain game for E-W in either major.
Well, we cashed our ♥ winners and declarer, after driving out the A♣, proceeded to cross-ruff his heart and diamond losers. In the course of this he led a spade from dummy and ruffed it (!) - this being the first spade trick played.
Finally, after playing off his trumps, he laid down the last spade from hand conceding the final trick. At this point both my partner and I spoke out. Declarer had obviously made an innocent mistake, he'd forgotten having led a spade earlier but I then faced all my cards to show where I'd followed to a spade earlier on. Was I right to do this before calling the TD?
Anyway, we called the TD at that point but by then dummy had shuffled her cards and was about to return them to the board. I'm not absolutely clear whether dummy did this before or after we'd drawn attention to the revoke. If after - surely this was an infraction by dummy, yes? Anyway, once the TD arrived, since dummy's cards had been shuffled, he said he couldn't definitely confirm where the revoke had occurred, so he asked us, would we accept the result as it stood, i.e. 2 down? But it was definitely not the penultimate trick.
Both my partner and I accepted, seeing as the revoke didn't actually affect the final outcome. Incidentally, we were the first to play this board, so I had no idea how we stood at the time.
It turned out that we had a 'bottom'. At every other table E-W bid and made game in ♠ or ♥. If there'd not been any irregularity, this would have been a fair result for us, due to an excellent bid by N-S.
But what about the possible revoke penalty?
I don't like gaining advantage from this sort of penalty, but as things stood, we were entitled (Law 64 A.1) to claim the revoke trick (which declarer won by ruffing) and one other, leading to 4 down and a certain 'top' (even 3 down would have been a top).
I'll put this down as 'lesson learnt'. But I think, next time I play, I'll ask that Laws be applied to the letter....