As a former ambulance crew who instructs lifesaving in my spare time, I can honestly say that giving a stranger mouth to mouth without a mouth shield (e.g. Resusci-aid) isn't particularly pleasant. Not actually required for effective resus, granted, and it wouldn't stop me giving assistance but given the choice I think most people would use one. Don't forget, there are plenty of bacterial & viral infections you can quite easily contract from mouth-to-mouth contact ! I have to say that I am surprised that Ryanar were unable to provide these items - I carry a pretty decent FA kit in my car - there must be room enough on an a/c. And a member of cabin crew saying they're "only trained to take a pulse"? That can't be true, surely? Taking of pulses hasn't been part of resus for ages!
Congrats to the nurses for keeping up the CPR for 40 mins, they must have been knackered. Unfortunately under the circumstances it seems that nothing short of neurosurgery would have made any difference.