> what it ultimately ended up being was rare but really obvious in retrospect, I think most doctors would have checked for it

I'm not so sure. Doctors are trained to check for the most common things that explain the symptoms. "When you hear hoofbeats, think horses not zebras" is a saying that is often heard in medicine.

ChatGPT was trained on the same medical textbooks and research papers that doctors are.

> ChatGPT was trained on the same medical textbooks and research papers that doctors are.

Yeah hm I wonder what the difference could possibly be.