Did the man have his put bull off the lead? Maybe he just wanted to go for a walk with his dog the same as you did? I can totally understand your fustration and picking your boys up because i would be the same. As far as the dog not being trained, alot of doggies pull on the lead because they are excited about seeing people or other dogs. Fair enough the pitbull has a terrible name for attacking dog and its an idea to always be safe than sorry but unless his dog was running around off the lead then i dont see what he has done wrong? Maybe his dog loves dogs and was just was excited to see them?
I am sorry i really dont mean to be sticking up for him but maybe he just wanted to walk his dog too because he had every right to be there just like you did.
Glad your little boys are ok tho, sounds like a lovely place you went for a walk
xxxx