As a guy whose dog can't get on her belly and give up quick enough, aggressive dogs in the field (or anywhere) really bug me. I've hunted with various breeds, males/females, intact, etc.
I'm sure that guy was apologetic and felt dumb, but IMO, if you're the guy with the aggressive/territorial dog, then you are the one that needs to kennel 'em up. Glad to hear your pup seems to have processed the scenario well.