I mean a lot of you might say no brawl, frenzy and blackout are all definitly dead. If they were definitly dead then why would optimus be fine with the army going to all the expense of dumping the bodies in the deepest undersea gorge on the planet. I mean you might say optimus didn`t know what they were doing but i doubt they would keep him out of the loop especially after he helped save them. And if optimus did know their plans and if the decpticons were definitly dead he would have told them not to bother because he is a nice guy and wouldn`t want them to waste their effort for no reason.... Military commander: It might cost us twenty thousand dollars per decepticon but in case they aren`t fully dead we will ship them over to that deep ocean gorge and dump them in so that they can never return. Optmius: Hold on. I like you humans and i don`t want you wasting your time. Those two are decapitated and that one got rockets to the torso. They`re as dead as jazz (god rest his soul) they ain`t ever gonna come back even for a sequel. Military commander: Really? Optimus: Yep they are d-e-a-d. Military commander: Ok we`ll leave em here in this scrap yard and just go get a bear. What do autobot`s drink anyway? As the above scene never occurred and as they did dump the bodies in that deep sea gorge to stop them from ever coming back, that means optimus was worried himself that the decpticons could come back. Which leads me to believe that decapitations and heavy damage to the torso is not fatal to a transformer just extremely debalitating (as one would guess it would be.) That also explains why the autobots were so gungho in decapitating their foes, if decapitation is neccesarily lethal to a transformer then they were being tactically sly as opposed to sadistic murderers. I expect then that jazz suffered the only permenant death. The autobot reactions show that he had died. That leads me to the conclusionm that extremly sever damage to the torso to the point that the entire body in split apart is the only way we have seen in the movies to actually kill a transformer. So jazz died because his body was wrentched in half allowing his spark to escape, blackout prob didn`t die becuase he only experienced outer damge to the systems inbedded in his torso.