@formerbabe How about murderers? If they're dying in prison and can be resuscitated, should we say this shouldn't happen because they've killed someone? How about a drink driver in a car crash? Should we leave them to die? You're on a very slippery slope here...
These examples have literally bollock all to do with a very, very simple concept, which is that you either opt IN or OUT of the organ donation system.
If you opt in, you can give/receive.
If you opt out, you can't give or receive.
(Oh and for what it's worth, in the real world, murderers, rapists and child abusers do quite often do get killed in prison, and no one is very bothered about it. Because they have indeed broken the fundamental contract of society.)