Pop had just lost a friend and was not in a forgiving frame of mind. For future reference, an "assault" (or battery) is a harmful or *offensive* touching of one by another. Doesn't have to be a punch or shove. And out west, from the vigilante days I suppose, a man isn't required to retreat but can stand his ground. But the old man used unreasonable force, self-defense, lucky he didn't get canned.
You did the right thing, like you I'll probably let police handle any discourtesy I might see directed to vets. But I won't `let it go' like a lot of civilians did then.
Thanks for your service.