I would refrain giving it a try. If he do something like what he's planning and the casino finds it out then there's more trouble to his money. It's better for him to talk seriously with the customer service and be outright on what has happened.
Things can be done peacefully if it's being made through talks and I think that the casino will spare him as it is his fund and didn't came from nowhere. There's a chance that he'll be given consideration.