Alright, second update...
Just got off the phone with the guy. The dog's name is Roxie, and lives outdoors. He says this is just the dog's disposition, and he can't drag her inside. She likes to be outdoors and run around. So not house trained. Also, Roxie doesn't like cats and small animals. But she is very sweet with humans. Not spayed, no rabies vaccine. He thought the dog was purebred when he got her, but doesn't think so anymore.
So, I definitely can't foster or adopt this dog -- I live in the city, I have like a 10 sq.ft. yard and four cats. However, I talked to him about some of the no kill shelters in the area and he seemed open to it. His wife also might have someone who is interested.
For what it's worth, he seemed like a nice guy, just very country. I think he was under the mistaken impression that all shelters kill the dogs and his feeling was "i'd rather put her down myself then have them do it". I'm gonna follow up and make sure she gets to a shelter.