One in a thousand multiplier means he won a huge amount, but I haven't checked how much he gambled, but assuming he needed to be created a whole new VIP bracket just for him? That means he gambled insane amounts of money as well, so he didn't just won 100 btc and lost zero, he did win the 100 btc part, but he probably lost a lot of bitcoin as well, remove that and you are left with amount of money stake could pay without a problem.

If you can check how much he played and how much he won or lost, you could probably see what he has done. I personally think gamblers who win this much eventually end up losing it all, because they think they can't lose this much and keep going and they end up losing even more.