What do you call a doctor that graduated medschool with a d+? You call him Doctor. Just imagine that. Someone that almost failed medschool will be doing your kidney transplant 
I must admit I'm a bit confused as to how all this relates. I mean, it's not even relevant to the Olympic medals discussion, let alone to the actual topic here, which is Mekkil's CR position.
But, now you've posted it, let's just correct a few things:
Anyone who can get through med school is "good enough" to be a doctor. The majority of knowledge comes from working as a doctor, and studying further while you're working (there are plenty of exams post graduation). Med school is there to provide you with the skills to be useful for your first few years until you begin to specialise and gain an in depth knowledge of that field.
In addition to that, I don't know how it works in the US, but in the UK there is a pass mark and you are either above or below it (generally there's a cutoff of what % of the year group can fail before they think about adjusting it). You get given a ranking in the year, but there is no mark for achieving a specific grade/percentage correct. Maybe in the US they do it differently, but that's their loss.
Secondly, I like how you're comparing academic achievement to kidney transplants. Anatomy is only directly tested in 1st/2nd year of medical school in most places, and from then on is essentially just tested by applying that knowledge. Someone's ability to carry out a kidney transplant is obviously not very heavily related to their knowledge of psychiatric disorders.
Lastly, at least in the UK, you'd call a surgeon Mister. They like to be special and go with a different title to doctor, although to be fair I'm not sure if that's only when they become consultants or from the get-go.
