To comment/discuss without Facts is to speculate.
So lets speculate.
If the passenger suffered a brain bleed, as reported, requiring CPR, it prob had affected her brain stem function. She would have been brain dead within minutes, but only a medic can pronounce, so most people 'die' after reaching hospital unless forensic/pathologist examination shows otherwise.
First Aid is exactly that. With a warm body any trained First Aider should be able to clear the Airway, restore/maintain Breathing & Circulation by ext CPR if possible until life extinct is pronounced by a qualified medic.
Rule 1 First Aider should not put themselves at undue Risk.
Rule 2 Patient should not be moved unless life threatened eg explosion,crush
Surgical procedures eg tracheotomy is not first aid How many scalpels/penknifes are allowed on board? The 'salad bowl' could be regarded as intubation, a risky surgical procedure - not first aid. A plastic film with a one way air valve and surgical gloves could be regarded as essential protection for the patient/first aider (Health & Safety)
As a first aider I would continue CPR and mouth to mouth for as long as possible or until relieved by a paramedic.
I am not familiar with current CPR guidelnes but chest compressions only are unlikely to provide sufficient air exchange to maintain life (snorkel effect)
Portable defibbrillators may be useful in certain medical emergencies if the first aider is current in cardiac resuscitaion protocols and authorised