An autistic doctor? Really?

Those aren't even remotely close to being apt comparisons. Autism does not impair one's ability to have a vast array of medical knowledge. In fact, it may help, as it does in Shaun's case.

So you’re pretty stupid, huh?

Well we can't say 'it's been done before'. That's what makes it interesting. It's different.

He hasn't progressed at all either he is still as socially inept as ever. I also very much doubt that in a litigious country like America that a hospital would allow Shaun anywhere near patients or staff.

The mentally impaired should not be allowed to administer medical care to patients, regardless of how much knowledge they might have memorized.

Or a series about a sadistic doctor?

The surgery aspect is where I find it most unrealistic. Things like overreaction to stimuli, nervous tics, other issues that could cause anxiety. Doesn't make sense to me to have a surgeon perform complicated procedures with those issues. Whereas extensive knowledge of medicine could obviously be an asset on a diagnosis/ consultancy basis