I think I'll change my mind on being an organ donor

I know the dust is settling on the organ donor debate but courtesy of mediocracy this letter that was in the Indy is making me have second thoughts about being an organ donor:

How dead are organ donors?

Organs for transplant have to be taken from still-living bodies, bodies still perfused by their naturally beating hearts, warm and so reactive that muscle-paralysing drugs may have to be given to facilitate the surgery.

Their owners will have been certified "dead" on the controversial basis of bedside brain-stem testing, a procedure not sufficiently stringent to exclude some persisting brain-stem function and which includes no test for what may be abundant life elsewhere in the brain.
Many or even most of those who have put their names on the NHS Organ Donor Register may have thereby offered their organs to be taken for transplant purposes on the (mis)understanding that the wording "after my death" on the application forms meant that they would be dead in the commonly understood sense before their offers were taken up.
If so, they have made their offers on a false premise and those offers cannot be regarded as valid. [FT: I assume he means morally valid; I doubt anyone will be worrying about the legal validity.] Had it been explained to them that they would be dead in only a notional ("brain-stem death") sense, at least some of them might have wished to specify general anaesthesia to cover the organ procurement procedure. [Or got the screaming heebie-jeebies about agreeing in the first place.]
David W Evans
Sometime Consultant Cardiologist at Papworth and Addenbrooke's Hospitals, Cambridge
23 January 2008