How did Wally go from wanting everyone to leave him alone to zoomies and play-bows? Sometimes instead of teaching a dog how to understand humans, our caregivers learn to speak dog.
Wally didn't care to approach anyone at the Sanctuary during his first week or two, he hardly let anyone touch him, so caregivers brought a friendly dog with them hoping that Wally would be more receptive to letting them leash him up.
Although he still wasn't ready to trust anyone, Wally hesitantly approached Tierney (a Dogtown team lead) when he saw the other dog, and allowed her to put a lead on him. Then they headed out to the play yard so that Wally could simply hang out with his caregivers and begin to figure out that they were not a threat. That was the start of a daily routine of taking Wally outside to do fun things in the hope that he would eventually learn to trust caregivers.
You can read more about Wally here.