For the current price, I believe this is really hard to believe to put on such amount. He must be a big whale or just some early adopter which hold huge amount of btc to gambling. And btw believe me I ever saw someone place 0.1 btc per bet too on slot games which have really huge payout around 200 btc but of course not here. This must be a crazy amount to get, just hope he does not spend it all