Seems like the site owner can just deposit 10 BTC and have a huge chance of winning.
I looked at the site and red flags pop up saying thats what is happening.
If you look only 1 person buys a ton of tickets and wins every time.
But that doesn't mean the site owner is cheating (because the game is provably fair).
p.s. but it might mean that there is a considerable conflict of interest happening every round...