well, looks like he cheated the system. I don't how he did that, but Stunna said that he'll post an article about it soon.
I was there when he won the first 1k and some people told the admins that they should check those bets thoroughly.. guess they didn't check enough
He apparently cheated by knowing his server seed. Once you know that, you can calculate what your future rolls will be.
I am still curious how he actually did that . Doesn't look like he just got lucky by figuring out the seed as following his win, there was another user who made 140 bets of 10 BTC and won all of them, which looked like done to show some kind of flaw.
So I am guessing he was able to figure out the seed due to some flaw in the system. Will still wait for the article from Stunna on it.