Being a practiced diplomat myself, from the moments I watched of that interview it looks to me that the owner was perfectly the fuck in her rights and acted appropriately to the situation. The kid went nuts, the parents failed to act, so she snapped a quick shut up. I applaud that.
As my parents did with us and as my brother did with his, if ever the kids should act up in a restaurant, you pick that kid up out of its chair and whisk it out of the restaurant before customers are further disturbed.
One of the few places I'd think to never mind tolerate that but accept it would be a baby crying in an airplane. The pressure is changing in the cabin, the baby screams, that kid you feel sorry for and just allow for the crying. In a restaurant there is zero excuse for it.