The 5 signs of obvious and irreversible death:
To figure out who is too dead to be saved, emergency responders look for five signs of irreversible death:
(a.k.a. livor mortis/hypostasis) which Jimi would have displayed if he had been dead for hours
(a.k.a. rigor mortis) which Jimi would have displayed if he had been dead for hours
Burned beyond recognition
CPR is only performed on bodies that have just died
Information about rigor mortis / livor mortis
"Livor mortis starts in 20–30 minutes, but is usually not observable by the human eye until two hours after death. The size of the patches increases in the next three to six hours,..." - Wikipedia. So it obviously wasn't observed, meaning Jimi wasn't long-dead and he was sent to the Emergencies ward for immediate assistance.
"Starting between two and six hours following death, rigor mortis begins with the eyelids, neck, and jaw.
Rigor mortis then spreads to the other muscles, including the internal organs, within the next four to six hours." - Wikipedia
"Rigor mortis is one of the signs of irreversible death and is an obvious justification for not starting cardiopulmonary resuscitation" Source