Yes, Navio should have done something. It's a sad commentary on society that the couple didn't have enough sense or courtesy to take the child outside. We never took the kids to "fine" restaurants, but when they got a bit older we'd occasionally take them to Applebees type places. And they quickly learned that if mom's dinner was interrupted,
no one was happy.
Now they are 12 and 14 and we rarely have to drag them out by their ear.