This whole thread is a perfect example of why I shoot Wildlife, Landscape & Underwater Images, People are just too much of a PIA.
In the situation of the Op, I can empathise, my initial reaction would have to be this dickhead was insulting me, being lumped into the potential pedophile grouping would have me considering a Lobotomy on the Guy, and sounds like the Op is qualified in that area, but, there's always a but.
Sometimes we just need to chill, look around and appreciate the other person's perspective (even if he is a complete dickhead), we are living in a fishbowl that's not really improving, our Children's future & well being is without a doubt our most important objective in life, if the chap had children in the Park, he's a concerned Parent with poor communication skills and the "soft" approach is recommended, if he's an individual in the Park with no Kids and comments, he's just looking for trouble, the "soft" approach is also recommended.
I spent 16 Years in the Army, the "soft" approach is not my preferred option generally, but the world's changed, and Im 64 now with the last 30 years of experience that I think really count, at 34 I think I may have gone for the Tripod Lobotomy without anaesthesia.