For this large amount they most definitely enforce KYC/AML protocol and them being a large casino from the sounds of it.
Would you know of any institution just handing over $100,000 in prize money and not questioning who they are giving it too?

If I am not mistaken, I have seen plenty of dice sites here process withdrawals of 10 BTC or more to winners. No questions asked. These are sites with extremely basic information required to sign up in the first place. MoneyPot when they still had the lottery jackpot, if I can recall, just let the user withdraw all 30 BTC that was won back then.