No, they didn't. Perhaps the NFL was negligent in not getting proper creds for the kid but the security guard who was doing the 'pork rind stuffing' was a representative of TeamOps LLC...not the Patriots. I'd be surprised if the contract with TeamOps LLC did not contain language that makes the Patriots organization not liable for any injuries sustained in contact with a TeamOps LLC employee. And the back of the deceased's ticket would indicate that.
“the security guard who was doing the ‘pork rind stuffing’ was a representative of TeamOps LLC...not the Patriots.”
Who hired TeamOps? The NFL and Patriots. I’m sure the contract does contain language as you say, it doesn’t really matter. Generally ‘gross negligence’ will void those types of clauses.
Once they invited the kid onto the field the terms of any contract changed.
a disclaimer on the back of a ticket does not necessarily provide blanket protection... just as when a parking garage has a sign that says “Not Responsible for Damaged or Stolen Property.” we shall see how the Boston courts handle this...