Organ "donation" happnes after a doctor declares you "brain dead" after a traumatic brain injury.
The only problem is that organs can only be harvested form an alive person, otherwise the organs
are dead and cannot be used for transplanation. People have often woken up just before they were supposed to be harvested and them made a full recovery. And you are not dead if you are "brain dead". Modern thought dictates that a person lives in the brain; a ghost in shell so to say. But nothing ccan be farther from the truth: The human body has two nervous systems: central nervous system (CNS) and central nervous system (CNS). A person is the orgnsim itself as whole.

Why? Qui bono? Follow the money: A brain dead person is worth up to a million freedom bucks when
cut up.

Organ transplant recipiens are in essence canibals: They consume the life force from other persons human flesh. Eventually they reject the organ and get a new old one or die.

How to protect yourself from dangerous diagnosis such as apnea-test when incapacitated? Fill out
a will-not-donate-statement (the from depending on your jurisdiction).