Mucked the best hand, WWYD?

I hosted a 24-player tournament last weekend. About 2 hours into the game (after the re-buy period), there was a hand that caused some trouble:

There was heavy betting between 2 players to the river. On the river, one player (the shorter stack) went all-in and was called by the other player. The first player showed 2 pair. The second player threw his cards face down into the center of the table. Before the cards even hit the felt, he said "I want to play those!", and grabbed them and turned over a flush. His cards came nowhere near any other mucked cards, there was no doubt they were his 2 hole cards. He said he meant to turn them face-up to show, but instead threw them face-down. Without the flush, he had only A-high, I tend to believe he knew he had a flush or wouldn't have otherwise made such a call...

The decision was made, his hand was dead, and the other player got an undeserved HUGE pot (he went on to come in first place overall, the other guy was crippled and went out a few hands later).

I hated to force that ruling on the other guy, he is a regular player at my games and wins less often than the other guys, in some ways I'd have liked to see him win one for a change. The guy who benefited from this ruling wins often when he plays (this has nothing to do with rules being rules, of course).

I'm getting to the point where I'm considering having people sign a hard-copy of Bob's Rules and the TDA tournament additions before every game. It was painful to uphold that ruling...


Rules are rules, but WWYD in this situation?