Hey
Hammer, why would you say that? Insurance? I would think that if the owner wanted to fly and take the ferry pilot as an 'adviser' who could take control in an emergency if both agree (e.g. in a ditching that the owner has no experience with) that should be permissible. Who would forbid it?
AFAIK, whoever takes responsibility and does the hands-on flying logs the PIC.
As long as only one crew does, it should be legal.
For insurance purposes, it should be important that there is crew with ferry experience on board, although I'd have to check that with the insurer.. not that they would really care who logs what, though..