Sorry, I must disagree. They did not use a technicality in the law. They raped the law. They manufactured the evidence, faked Terri's "wishes" and put her to death by a direct order from a judge acting without authority (ultra vires). There is NO due process in American law for violating one's unalienable right to life, save only if it is forfeit by conviction for a capital crime.
You are 100% correct!