If this is your moral viewpoint ...
... then perhaps you should reconsider playing any advantage game in the casino. After all, what we are talking about here is a matter of degree, not kind. In the instant case, the casino freely offered slot machines with skewed payouts. These payouts gave the players the advantage. A player took advantage of that and made some money and the casino kidnapped him for awhile. You believe they were right.
If that is what you hold to be moral, then you should never play a full-pay deuces machine or a 10/7 double bonus machine. When a $1 9/6 progressive gets over $5K, you should not play it. When the casinos offer double or triple cash-back points on some days, stay away from any 9/6 JOB games. If you play the horses and you see a horse that ought to come off at 9:5 coming off at 3:1, don't play that horse. If a casino is offering a 2:1 blackjack game, stay away from that game. When the count rises to +2 or more, you should leave the table. If the dealer makes a mistake and exposes his hole card to you, point out the error and ask that a misdeal be declared, or simply play the hand as if you didn't know what his hole card is. If you happen to find a roulette wheel that is off-kilter enough to change the odds, don't play that wheel.
While we're at it, maybe the casinos ought to post signs that compare the true odds in their games to the actual payouts and make it clear to each patron how big the house advantage is in the game he or she is playing. That way, if a patron engages in the mistaken belief that he or she can beat the casinos in a game like Keno, for example, he or she will know the truth. That would be the moral thing to do by your standards, would it not?