As a parent - and I do NOT have a parenting license - I happen to know that a child's bad behavior is best corrected when it happens, not in a discussion group a couple of weeks later or even at the dinner table, a few hours after the fact. I don't know what I would do if my kids made a scene in a public place. They happen to be rather well behaved and they never do that but, let's say they demand that I buy them some toy or candy and then throw themselves on the floor and start screaming and convulsing (I saw that happening in stores) I know that I would take the first opportunity to 'discuss' that behavior with the kid 'in private'. I have no idea why that woman was slapping her daughter around and THIS IS THE POINT. It's not clear either WHAT she was doing or WHY she was doing it. And, again, there are thousands or tens of thousands of similar 'beatings' if you want to call them this way, happending in this country every single day. Some parents are harsher than others and some go way over the line. Some kids need more discipline than others and some just won't respond to anything and are to see the death row soon after they turn into adults. Some parents kill their children and I believe I heard of children killing their parents. I also heard of children killing or dismembering or raping other children and of parents killing each other or other kids' parents.
I am sorry we live in an imperfect world but, I am sorry, a mother spaking her daughter while on camera is NOT national news except in this voyeuristic, brain-dead society of ours.