Nate's Tickets writes, "What will/should the casino's responsibility be in this case?"
One thing I'll guarantee you, there will be lawsuits, against MGM and maybe other business entities.
Gargantuan damages + wealthy defendant + tiny chance of success at trial can = attractive lawsuit.
You can all probably think of lots of past examples of this. These cases can be really junky, to me it's aggravating, but that's how it is.