Wow, thats really generous of the casino. It also shows how much money a casino makes being able to afford these kind of mistakes.
Who knows where they pulled the money from. Even if they could technically afford paying out this much, hard to believe that they would not have at least taken some hit. They probably did not want to deal with lawsuits as I think that would have been the consequence of this event. That would have been more expensive, I believe and would have just wasted their time as well.
This has taken them some hit for sure but they know where to get it back, so they're for sure going to recover it through the other players. When this news blows to their local and it'll make a lot of gamblers think that any amount that they'd won, this casino is going to pay them out. The marketing is also part of this blow and they're brilliant with that even with some glitch. It's not only about satisfying their customer but also, trying to get the crowd through this one big decision that they have made.