After he had and cared for the dog for six years, he didn’t want to have the dog taken away from him, which is only natural — he clearly loved and took good care of the dog.
And maybe the dog ran away from the first owner because he didn’t like the first owner, did you think of that? And maybe the dog was very happy in the home of the second owner.
And maybe the rightful owner would have taken him to the vet once a year. Did you ever think of that?