Yes, I know what they say about hindsight

I hate, hate, hate when I am confronted by situations where I have to think on my feet AND suppress my initial response because I want to try to get my point across rather than just insulting the person so she'll leave. Usually in these cases, I end up reacting overly polite and then going over the situation in my head later and getting irritated because I didn't stand up for myself.
Friday mornings between 8:30 am and 9 am , Echo and I meet our friends, Jana (human) and Steinway (dog) at the dog park at Victor Ashe park. We like to go then because the dog park is usually empty. Echo gets nervous around big packs of dogs and ends up just sitting next to my feet. Steinway has a more aggressive response, and Jana doesn't want her around more than two dogs at a time right now. Our dogs usually spend most of their time sniffing around the park, ignoring each other. Around 9:15 am Charlie (dog) usually shows up. After about three weeks, Echo and Steinway made friends with Charlie, and the three do okay together.
Last Friday, after Charlie left, another lady drove up with her dog. Even before she got out of the car, her dog was leaning out the window, barking at our dogs. We asked if her dog was okay with other dogs, and she replied, "He's never really been around other dogs. We've had him two months, and I thought I'd try this out." Great. Jana and I quickly put leashes on our dogs so the three could meet each other one at a time. Echo crept up to the dog to sniff noses, and the dog immediately growled and then snapped at her! Same response to Steinway.
Then, the lady looked at us and said, "Okay. I guess I'm going to try taking him off his leash and see how it goes."
WHAT?!?!?!
We quickly headed off to walk around the greenway. The woman rather fakely apologized for running us off, and what galls me is we both just fakely reassured her that this was our normal routine. (The walk is, getting run out of the dog park by crazy lady is not.)
I've been running through it in my head since then and have come up with a polite (and very articulate) version of what I wish I had said:

Your dog has snapped at both of our dogs without any sort of provocation whatsoever. I don't feel that our dogs are going to be safe inside this park with your dog off-leash. Since you insist on taking him off-leash in spite of his previous response, we are going to leave the area and protect our dogs's safety. Please wait until we are outside the fence before removing your dog's leash.

And a less polite version (aka "My Initial, Suppressed Response):

Look, crazy lady, your vicious, nutjob of a dog has already snapped at our two dogs without any sort of aggressive behaviour from them. If you take your dog off its leash right now and it goes for my dog or me, you can expect my foot to make rather fierce contact with your dog's ribs. How stupid do you have to be not to see that taking your dog off-leash is a bad idea?

(I tend to ramble more when I'm rude.) HA!
I'm going to try to remember my polite response if she shows up this week. Not that she'll listen or agree with me, but at least I'll feel better about my response to the situation.