Air Accident Investigators do not decide when to call off a search and rescue mission - this would be in the hands of HM Coastguard.
When the boat brings in the first "body", Dr. Ryan checks it and then shouts that there is still a pulse (i.e. the heart is beating). She proceeds immediately to give CPR, which would only be done on a victim with no pulse.
Towards the end of the episode, pathologist Dr. Sam Ryan is driving off to speak to a survivor - who is in a coma and on a ventilator. A phone call to the hospital would have saved her making the trip.