That seems reasonable to me.
However, after having worked for 25 years in the medical field...the first time someone came up who needed an organ who was not a donor...it just wouldn't apply. I can see the sob story headline now: "Medical Center refuses lifesaving procedure to the father of family..."
There is that potential, I agree.
I thik it can be countered by having a good deal of coverage and a well publicized registration period prior to the intitiation of the protocol.
Plus I wouldn't actually refuse a non-donor, I'd just put them at the bottom of the potential recipient list. That way no organs wold go to waste and there'd be a clear cut, good reason why the guy didn't get the transplant: someone else did.
It is also my hope that such a protocol would result in so many organs being potentially available tat the subject wouldn't arise.