My 2c:
1) Yes, there is a certain amount of 'buyer beware', naivete, and fear involved in all these stories. AND
2) This game is a scam
Here's a link, although google will turn up many more:
Antigua & Dominican Republic Casino Scam Alert!!
sound familiar?
Here're a few points to consider:
Speaking to a casino supervisor about this issue is a waste of time. You will get nowhere.
Your passport doesn't belong to you, it belongs to your government. You aren't allowed to surrender it as collateral on a debt (or a rental for that matter)
You don't necessarily need your passport to return to your country. Your country likely has an embassy, consular service, or agreement in place with a country that does. If you're getting extorted because they have your passport, call your embassy. they'll get you home
There is a legal process involved in collecting a debt. Thugs threatening you is illegal. Again, call your embassy. And your tour operator.
To say that a casino isn't responsible for the table because it is a subcontract is ludicrous. Of course they're responsible for what happens inside their walls. Otherwise every game and machine would be on a subcontract. And every waiter and barman would be an independent contractor. And the parking lot would be a separate entity.
Also, a casino requires a license to operate. For a license to be legal, it has to be issued to a hotel (there have been exceptions made). This, among other reasons, is so that there is a fixed asset for the government to attach in case the casino gets behind on its payments. For all that you subcontract to a casino, the hotel is very much responsible for what happens there. And the hotel, even if it subcontracts the casino, is still benefiting in the form of rents (or even %) and in many cases is helping collect these debts.
Personally, if I see one of these games in a casino, it tells me everything I need to know about the integrity of the whole joint -- it has none.
And for those that are all about the buyer beware: sure, they may have been suckers to have been suckered. But the people who took them for that money did it dishonestly. If you lose your money in a straight game, I have no patience for you. But if you lose your money in a ponzi scheme, or a keno game, or a rigged deck, that's a different matter. You got screwed, and you got screwed by a douchebag.
That a hotel not only doesn't help you out, but aids and abets in this is well beyond the pale. Were that to happen to me I would definitely log my complaint with the tour operator and look at lodging a complaint against your tour operator either in court or with the appropriate regulatory body back home. Win or lose, the tour operator is not going to want to fight the battle and may very well pressure the hotel to both ditch the game and refund all or part of your money.