I don't know what on earth the person is thinking, with good amount of money that will risk their luck in a non reputable site.
From BTC0.7 winnings, I'm sure OP started with a big capital to reached that amount as profit. For a person who holds that kind of good amount, I'm expecting their DYOR is much better compare to average gamblers but still OP ended up on that kind of site.
Based on what I've read on their ANN, I don't think it's a personal issue why the owner became inactive. More of, I believed they really tend to scam at the start.
For newbies out there, stay away to the site as it was still active and running.
There is also possibility that his winning also came from just small capital. Since it's not that trusted website I don't think some one will just deposit big amount to the gambling site that he never use before . For what ever reason is even they have event that promise a good bonus this still no way you will just trust your money to not known websites just because of bonus.