Well, it wasn't me folks... honest! I haven't visited my GP's surgery for a while because MrsProf is a professor of medicine herself and gets her prescription pad out when I mention my aches and pains.
Seriously though, this guy needs a reality check and my view is that such behaviour should be brought to the attention of the university authorities, assuming that he remains employed. He is bringing his university into disrepute by acting in this appalling, conceited manner. I've met more than one retired emeritus professor with huge chips on their shoulder and personally, I've no time for them.
I'd really like to meet this vainglorious individual and see how he reacts to being in the presence of an Oxbridge professor. In all my years in academia, I've never been in a situation where I've felt the need to respond to a member of the public in this manner and I fully endorse the suggested responses above. I'd respond the same way myself!