I think his problem with the credits stems more from the fact that that mewling, talentless wench is collecting royalties than anything else. Consider the fact that Paul didn't do anything like this when John was alive.
It's one of the most popular songs in history...he wrote and recorded it alone...and Yoko fucking Ono gets half. Put yourself in Paul's shoes and let it simmer for thirty years.
Anyway, switching the order is no big deal. It's Yoko who's calling attention to this cosmetic change, not Paul.
