Adoption Group Wants To Take My Mom's Dog Back. Can They?

Hey all. Thanks in advance for any advice I recieve. This has been tough for us. Posting this for my mom on her behalf. Going to try and keep emotion out of this to try and stay objective.

About 2 weeks ago, my mother adopted a dog in North Carolina from a group that rescues mexican street dogs. She went through the interview process with them. They came and inspected the home and brought the dog over to make sure she seemed fit to have a dog. She has a fenced in back yard. The fence is very tall so no dog could jump over it. Everything went well and the adoption papers were signed.

Yesterday, my mother left for work in the morning. She was not able to be home in the middle of the day like usual to let the dog out, so she left her uncrated with access to the dog door that leads to the fenced in back yard. While she was at work, she got a call from one of our neighbors saying that the dog was in the front yard just sitting on the drive way, and the back gate was open. The dog never left the property. My mother promptly had one of her other neighbors (who she's closer to. We'll call him Dave) go get the dog back into the house.

When Dave got that call from my mom, he went with a spare key to get the dog back in the house and block the dog door. When he arrived, he found the dog had let herself back into the house and was waiting on my mother's bed. All was good

Well, somehow the group she adopted this dog from found out about this, and called her that night saying she was unfit to have a dog, and per the adoption contract would come by to take the dog back. Again, I'd like to keep emotion out of this, but I think it's worth saying that my mother loves this dog, and upon getting the call she was speechless and started crying and pleading that it was just a mistake and wouldn't happen again. She is incredibly distraught.

I've been trying to find legal resources and precedent for this but it's difficult to find. From what I can understand, the dog is seen as property in north carolina, and if the dog is my mom's property, I don't see how they can take the dog. Please help.

TL;DR: My mom adopted a dog. The dog escaped but never left the house. Adoption group found out and is saying they are coming to take the dog back