It is in Nevada that the courts said that the casinos can boot a person for any reason (assorted SC rulings and fed laws do limit that a bit). Many states limit the various casinos in a manner reminiscent of utility companies (state sponsored monopolies). This is the case in places like IL, where the casinos are far more limited in who and why they can boot a person.

Interestingly there are a few groups of lawyers who think the law has changed sufficiently,and Las/Nevada's role in gaming and the nationalization of gambling all lead to the conclusion that the earlier broad ruling would be reversed. And in any locale where casinos are under a 'utility' setup as opposed to a 'neighborhood bar' setup, assorted individual rights to access exist.

There is a firm in Las Vegas that actually has an attorney and staffers positioning themselves for the right case to rechallenge that law.

However, since they approached him away from others and he went back without taking any action, they had valid grounds it would seem to me. I also find it presumptuous that he would ask for a comped room while playing poker. I do like the idea of giving them acess to the spa and toiletries.