Boy do I know how you felt :-) my 8 year old daughter had a similar nose bleed on a fight to America. After 45mins I was thinking 'Is there a Dr on board?' it stopped but not until she had filled up two carrier bags with little bloody tissues. For what its worth I think that you would have been within your rights to call an ambulance, I've no medical experience but I don't think that Tom or any of his colleagues would have thought you were wasting their time. BTW the best way that I have found of stopping them is to pinch the nose really hard and push upwards and don't let go for at least 5mins.