Second, even if the parent's were negligent in some fashion, that doesn't mean Disney wasn't also (and vice versa). When the answer gets filed, we'll see some type of "but the parents were negligent too" type of argument.
To win, you can't just prove negligence. You have to show the negligence was a direct cause of the injury.
We will find out. I'm only addressing whether Disney is negligent, not liable. I can't say whether they're liable until Disney makes their allegations regarding the parents' actions.