IAAL, but I don’t know jack about Nevada gaming law, and this surely isn’t legal advice–just spouting unresearched opinions on the interwebs.
Unless the law specifically says that what he did is illegal, it strikes me as odd that what looks an awful lot like like negligence on the casino’s part would translate into liability on the player’s. I’m paraphrasing and probably misremembering torts, but my recollection is that negligence is a failure to exercise reasonable care under the circumstances. And I’d say that the extraordinary precautions casinos generally take to catch cheaters means that “reasonable care” under these particular circumstances is a pretty high bar. Heck, even if the law is on the casino’s side here, my gut (that famous jurist) says it should lose.