I wonder, is he an actual physician, or did he buy a qualification, or is he a doctor of something unrelated, or focused in one small area? Perhaps he's a proctologist, that might explain the obsessions.
Those medical errors bother me, surely even a doctor on the rocks wouldn't get the thing about Shepard's Meniere's wrong. I suppose he could have been bluffing and hoping no one would pick him up on it, his ego would make him think that that would work.