Is there a Doctor on the Plane? ID Fraud and the GMC

I was recently flying back from the Mediterranean on RyanAir. Being posh and rich ;) Matron B and I had booked seats and we were sitting in the front row. A third of the way through the flight, I noticed the air hostess (are they still called air hostesses?) run into the galley, grab a handful of sick bags and ran back to the main body of the fuselage.
Five minutes later, the same hostess came to the front, a couple of feet away from me, grabbed the public address microphone and said those fateful words - is there a doctor or nurse on the plane? Oh bloody hell ! Unhesitantingly, my dear wife (who is a senior nurse) stuck her hand in the air and said, pointing to me 'he's a doctor'? The trolly dolly (sorry air hostess), then asked me for some kind of ID. I showed her my expensively acquired (yes it's a whinge !) BMA membership card. I asked her what kind of card she would normally expect to see and she said that a debit/credit card with Dr. on it would suffice. In recent years there have been many non medics in politics and dare I say it in Nursing who have got a PhD & who address themselves as 'Doctor' . So, I suppose John Reid ex Labour Scottish Rottweiler and SOS for health, might have got away with it.
I attended to the patient and thankfully she recovered fully after spending a period lying down across three empty seats. At the end of the flight, I was asked for my professional number -( the hostess explained that they have had impostors posing as doctors in the past.) I took this to mean my GMC number. Now it is only in the past 2 years that I have bothered to memorise this - nonetheless I was quite pleased that she was making the effort to confirm my identity as a doctor. However it occurred to me that GMC numbers and associated names and surnames are publicly available on the GMC website. In the UK, one would not need to try very hard therefore to impersonate a doctor with a degree of conviction. Surely, some kind of GMC issued card with picture ID is required? I am surprised that stealing of medical identities does not occur more often - I suppose it requires a certain degree of pathological nuttiness that is not very prevalent in society or that impersonating doctors is not very lucrative - the latter I suspect.
I am one who normally eschews regulation, but I hope it does not take a tragedy to persuade the authorities to do something about it.