I've heard from a Vegas lawyer that basically all of the serious law firms there do some amount of business with each of the casino chains. This is intentional on the casinos part, and gives the law firms a very simple conflict of interest claim when someone wants to sue a casino.
Combine this with the fact that Nevada doesn't allow out of state lawyers (and passing the Nevada Bar requires a considerable investment in time), and as a consequence the only counsel you can get to sue a casino amounts to the sort of low-budget lawyer you might see advertising on a billboard.
If I had enough money and brass, I'd hire a bunch of promising attorneys from out of state, relocate them to vegas, get them certified in Nevada, and then create a firm specializing in suing casinos. I'm sure there's a fortune to be made (if you don't get bought/killed by organized crime)