The payout system does not seem to be FIFO, that is, just because you put in money before person B does not mean you'll get paid out before person B. I also put in 1BTC (far before these people) and followed it up with a small transaction. The small transaction got paid back (also incorrectly) whereas my 1BTC was never returned. Oh well, it was fun to watch.
I've lost more in casinos and left with a "oh well" attitude too. Pretty sure plenty of people have. Of course, I've also left casinos with "fuck that sucked" attitudes, and also "look at all the money I just won" attitudes.
https://blockchain.info/address/1Gh2tRaqaPWFbQVabVD9rPsN1nm9...
https://blockchain.info/address/1BYbqzLvAN9PCC4LqNPPG2dHSyTn...
I'm going to watch and see what happens to them. If they don't lose their 1 BTC, then that's at least slightly interesting.
EDIT: It's been more than an hour; no repayment yet.