FWIW, I used to carry lollipops in my purse. If I saw a kid melting down (or a parent clearly at the end of their rope), I would speak directly to the parent, saying something like "My son had a day like that Wednesday! I have a couple of lollipops you are welcome to if it will help you get done here in peace." I only had one bad reaction from a mom.

Of course, when it reaches the kind of extreme Tessa witnessed, I would agree it is a police matter.