Excited/submissive urination ever since visitor screwed up
So, about two weeks ago, I sold my fridge on craigslist. A girl who came to look at the fridge took one look at Khaleesi, was like "OMG a german shepherd!!!" and without asking, picked her up and starting hugging her.
Khaleesi hates being picked up and hugged, even by her family, so you can imagine what she was like from a stranger. She was squealing and barking and squirming around, and I was like "ummm, she doesn't like that, can you please put her down". So the girl put her on the floor, and she promply peed on the floor, and ran away, tail between her legs. Ever since then, every time a visitor comes over, she takes one look at them, and pees on the floor. I don't know if it is out of excitement or fear.
Othan this, she has ZERO accidents in the house. So I don't think its a housebreaking issue, it only happens when a visitor comes over. She even does it with our friends that she has met multiple times. What can I do to stop it?
P.S.- she is in puppy kindergarten, and I also take her on walks and to the park, and allow strangers to greet her and give her treats, in order to give her positive associations with people.