Sandra, you are totally right, urination can be a response to fear, anxiety and is often seen in very submissive dogs. It is one of the most common problems that I see. People think they have a house training problem as the dog can't wait to pee when they get home and they can't get it outside fast enough. - I have to say that I love these cases because a) they are easy to see what is going on and b) I can leave happier dogs and much more sensitive owners when I leave!
A fearful or submissive puppy is highly unlikely to jump onto a sofa to pee though - it could happen and I can see how it would. From the situation described this is not the case here.