An AED is pure electric activity. If the patient has no mechanical ability left in the heart an AED will not help.
CPR is pure mechanical activity and a bridge to return to life if the body is up for the challenge.
Marlise Munoz had the resuscitative measures and her heart restarted, but her brain did not. She had the bridges to return to life applied, and they failed. She died by neurologic insult. There will be no braindead person that was diagnosed by current guidelines that will wake up and disagree.
Sorry for the scattered thoughts.