To be quite clear,there is a Big difference between reporting a dog running loose and defending your family.
The first is up to the authority, who may or may not take action. In the case of the second? Make no bones about it, if I feel my family is threatened (I can usually tell the difference between bravado and a genuine threat), I do not back up a single step.
If there is a threat, I fully intend to meet it with overwhelming force until the threat is resolved.
A friendly dog trying to say hi to everyone can be annoying and I may say something about it, but if it were a perceived threat, there are no warnings given.
Now, a jerk next to us who refuses to control his (non-threatening?) Dog may be granted the, "I am about to defend myself" warning after the second time.
If a ranger comes by, I would likely mention it, if it continued to be a problem. In our experience, they are usually friendly and helpful, but I wouldn't rely on them to defend me in a confrontation as the OP seemed to fear may have happened.
Sharing space requires flexibility and tolerance from everyone. There is a hard line when safety is a concern. But you do need to pick your battles. It's not the same as rolling over when faced with a bully.
It's about making smart choices and showing extra patience when possible.
Hope this clarifies my earlier response.