What would you do if your dog was attacked by another dog?

I was walking my very social 25 lb terrier mix on a leash. Another dog jumped out of the car he was in, ran across a parking lot and halfway down a bike path to attack my dog. Mine was totally surprised. He was not hurt and the owner came and retrieved his dog with apologies. I'm worried that this dog could attack a child. He was completely unprovoked. Should I turn these dog owners in to the condo management? I blame bad dog owners, not the dog.