The idea of getting someone else to proof-read your work well and truly predates ITSM and ITIL, and with good reason.

Jim, I think everyone would agree the resource charged with providing Service Validation & Testing as well as Evaluation should definitely work very closely with the RAD Manager. I'd go so far as to say that such a relationship is essential. But that's a very different kettle of fish than suggesting that those two roles be invested in the same person.... my own observations from experiences within several different process areas is that it's just a Bad Idea(TM).