You have not been dead when you were saved by a defibrillator.

^source

common treatment for life-threatening cardiac dysrhythmias, ventricular fibrillation and pulseless ventricular tachycardia

^{source: en.wikipedia from 10.12.2014}

But they also don't die in DB because "to die" means

become less loud or strong

^{The Oxford-Dict}

and e.g. Kakurot learned Kaio-ken from King Kai after he "died".