The problem with that is that he is a gp, not an endo, not anyone who has done anything above bachelor degree in medicine. Outside of GP doctors, who get the title because of tradition, not study, the title dr is reserved for those who are specialists in an area... PhD specialists with an ability to research. He doesn't not have this background or ability, or any qualifications above a basic bachelor level in general practice medicine. If you read anything he has written, you would see that is plainly obvious. I think that, without the proper research level and background his doctor title is misleading. It is for that reason, if I am a doctor of technologies, I am not aloud to use my title doctor when publishing in medicine, as it is misleading and lends undue credibility to my work.
So, no, I do not believe it is farcical to question his title of Dr in this area.