Reading "he jumped into my life with his not particularly conventional social approach" and reading about the dogs behavior, it may have been more about your friend.
Reading Tony's description of dog in the dream dictionary makes me wonder if you have felt uncomfortable , irrritated or even angry with your friends social skills and how he might approach you or interact with you. My comment about a dog responding to yes or no commands....I was wondering if you had thought about or want to talk about those feelings with him and/or set boundaries with some of your friends behavior.
Of course, everyone is a mirror for our own behavior....so you have hinted by asking whether the dog is about you or your friend. Have you crossed others boundaries with some of your behavior? Sometimes other people need to negotiate and re-negotiate boundaries with us and us with them.
You seem like a very thoughtful person in regards to your relationships.