I answered a question along these lines a few weeks ago when someone asked exactly what a radiologist does. It sounds to me that this man is taking you for a ride. All radiologists are medically qualified and undoubtedly he should know that the phalanges do not have individual names in the strict sense.
The fact that he "may" have studied at Cambridge but hails from Scotland is irrelevant as to many, it's the prestige of the oxbridge universities that matter along with their reputation. However, no matter where he studied medicine, he'd be in uni at 19, so again that's not relevant. All in all, when you combine the Cambridge aspect with being there at 19, it looks like he's portraying himself as a prodigy. The funny thing is that I know the names of the majority of the exceptionally talented medical students who have passed through oxbridge myself, so I'd be able to tell you if he was genuine.
In the meantime, the following link should help you.
http://www.gmc-uk.org/
On the homepage, click on "Check a doctor's registration". This will open a new window. Leave the "GMC reference number" box blank as well as the GP register part. Under "given name" enter his christian name and select "male" as his gender. If he's qualified, his name should come up in the lists after you click on "search".
If you can't find him listed, confront him and ask him for his GMC reference number. This is the number that appears above your GP's name on prescriptions that you get from your GP Surgery. If he can't give the number to you off the top of his head, he's lying as all doctors have the number ingrained in their brain.