Will be interested to hear more about this - as it stands, it sounds like almost a carbon copy of the Crockfords incident except that in that case, Ivey is suing them for his money.
I take that to mean that the Borgata actually paid him on the night, as opposed to Crockfords which withheld his winnings. As low as it was, I could at least understand what Crockfords was doing him (they were basically trying to freeroll Ivey, hoping he'd lose despite advantage playing).
For someone working in casino security it should be pretty easy to spot someone who's edge sorting. Especially in a case like this where they're having a member of the casino staff turn specific cards for them and keep them turned the right way. I gather it was a lesser-known technique back in the 2000s... but we're talking about 2012 here, a major casino like the Borgata should have been aware.
I'm not a lawyer, but IMO once they see him turning cards and they let him keep playing, and especially when they've paid him afterwards, they've made their bed. It's something that's easily prevented even with "defective" cards by just including a turn in the shuffle procedure. So I'm struggling to see how the casino gets to blame anyone other than themselves. One assumes the casino approved the card design before Gemaco printed them, so they might even have a hard time trying to sue the printer...