Here's my take on this: First off, make it a goal to raise your kids in a way that no one will have a reason to blather on about "If that had been MY kid.." or "If I'd have done that when 'I' was a kid.." And bingo, bango- problem solved. Barring that, those phrases are most definitely passive aggressive digs at someone's parenting. To suggest otherwise is ridiculous. For a child to respond with "Try it and I'll call the cops!" is disrespectful and bratty. If the child's behavior warranted a comment, then you (as a parent) should address the behavior (and if it were me, address the passive aggressive comment-maker because comments like that are NOT okay). If not, then you (as a parent) should defend your child in a respectful way. This shows your child that you're not going to leave him swinging in the wind when an adult gets out of line. Also shows him that not ALL adults are right all the time. That's important for a child to know, to keep himself safe.