Backdoor flush, down the toilet

Played a 51-player tourney tonight for a modest 50K buy-in. The first part of the tourney was a bit of a blur as I was trying to play another tournament at the same time, and on two successive hands I accidentally folded AK, and JJ while diverted elsewhere. However I managed to maintain a decent mid table position and then the hand that follows came along and I flopped a straight with K 9 and an opponent threw his chips at me.

following this I won 3 more pots in successive hands and seized the tournament lead.

Then this happened:

I had a pair of Jacks and played the hand fairly gently when a threatening flop came along, but the river brought me a full house when the Jack of Spades fell, also giving an opponent a backdoor flush (nearly a royal flush, but not quite). Naturally, as this is RP, he triumphantly threw in his whole stack against the full house, and went for an early bath. Opponent was ranked in the top 1000, too, so always pleasing to take down player with 30 million chips in his account.

This gave me a large tournament lead, but I coasted downhill and faded later on due to a dearth of decent cards and a couple of bluffs that backfired when the victims refused to lie down.

In the end I finished in 5th place and picked up a couple hundred thousand chips in prize money, but was a bit disappointed not to do better after leading for a long time. Still, by the end had hit an all time high chip count and hoping to do play better next time out.