Mandalay Bay owner files complaint against victims of Las Vegas shooting

I don't understand why this would be Mandalay Bay's fault in the first place, how should they be expected to defend against something like this?

We can go around and around about who's at fault for this shooting and America's gun violence problem, (and we certainly do here in the states) but it seems the hotel the gunman shot from would be pretty low on that list, and their move to limit their liability strikes me as a smart, if cynical move.