I have seen a guy loosing 1000 bitcoins in just one bet on justdice and another guy loosing more than 300+ btc on pd. but at that time btc was much less than 200$. This guy is really crazy or too rich to afford that much of money.
Omg, Its too big amount to lose, I can't believe why he put this high amount of btc in gambling games. As i think now 1000 btc it's worth 5853k$, It's really a crazy guy to do this bet. Maybe as you said, he is too rich to put this high amount in just one bet, or maybe he is too crazy like i said.