Former medic for 8yrs here. So, let's say this was a mass casualty; the START triage says to check for breathing, reposition and check again. If no breathing then black tag. The coroner found this person alive because she was breathing. Problem solved. Who cares about pulses.
I can say there has been more than one occasion where I have gotten on scene and said, "Oh, ****, there's no way that injury is compatible with life!!" and then find myself running hot to the hospital 5 minutes later. Contrary to popular belief, exposed brain matter is not instant death criteria.
On top of all that, I worked in 6 different systems in 2 different states all of them had protocols that had us run a strip of asystole on *all* black tags (once backup arrived in a mass casualty), dnr's and drt's. Even decaps and hemicorpiectomies. Problem solved again.
And definitely, when back-up finally arrived they should have re-assessed the patient, not just leave it for the coroner. Problem solved a third time.
Like someone said earlier, it's easy to be an armchair quarterback, and I can't really pass judgment because I wasn't there, but it seems like some checks and balances were not there.