This is just my opinion, but from what I just read I cannot imagine a scenario where this all could be true.
First: I one wins 76 000$ it’s VERY unlikely that such a lucky player would lose it back.. and so fast – no way, unless hes hitting the big tables and 76k is no biggie for him/her(very unlikely).
Second: You say he deposited 100$ as his first deposit and now suddenly has means to deposit 20k after losing the 76k he had won??? Quite a strange player to me 
There is however some different sides that also make this sceanario even more confusing.. now if a casino would like to take away your hard earned money the surely wouldn’t need to go that much overboard as hitting 76k WINNER – Unless ofcourse you are a super affiliate – VERY SUPER 
:D:D