I just find it hard to imagine that with all he's done in his career, Paul feels like he needs the ego gratification from asserting his ownership of any particular Beatles song. I can't see Keith Richards, for instance, getting pissed because the credit on Satisfaction reads Jagger/Richards, since Keith came up with the riff and the riff IS the defining element of that song. I know it's different because Paul wrote Yesterday all by himself, but so what? You made a deal, stick to it. Maybe if he stopped worrying about stuff like this, he could come up with some songs that are better than the crap on his last few albums. Run Devil Run is the notable exception, but he didn't write most of those.