When you put it like that...
Her: "Oh, so did you get to keep the dog?"
Me: "Nope, he's still in training. We think he's going to pass, though."
Her: "So you have to give him up?"
Me: "Well, that was the deal. That's what the contract says."
Her: "Oh, I didn't know you get paid."
Me: "I don't. This is volunteer."
Her: (Long pause) .. "So, you don't get paid .. and you give up the dog after all that work?"
Her: "Oh." ... backing away as you'd deal with someone you think might be insane.
I suspect she won't be scheduling playdates with "Crazy Mom." Some things don't need to be said.
It does occur to me that the question of "why" is one that I've never really answered here, but it's late and that's for another post. .. once I've figured it out myself.