Sadly, this is the norm: Misdiagnosis. Intentionally being misled for unwarranted surgery. Inexperienced surgeons.
Pets: Everything from Veterinary. Ladron misdiagnosed our dog with Kidney Disease), leading to a good two years worth of the dog chowing on Kidney treatment dog food, only to come to the USA and be informed our dog never had Kidney Disease. He had another major issue that was quickly remedied, and then went on to recovery from the poor diet prescribe by that vet.
Human family member: Our pockets were deep (we encouraged all test and review with Quality Care at the helm) but they missed diagnosing cancer. Cancer went undiagnosed until later stage, when we happened to be in the USA and did a second review of all.
Why did we trust the doctors? For exactly the same reason as others here have stated. We were told the medical care was so wonderful. We foolishly believed this. After the fact we met several (3) other expats who had late stage cancer that the doctors missed diagnosing in Mexico.
If we had it to do again, we would have moved to Mexico, but returned to the USA for reviews. Shame that the expats are so, what is the word... blindly raving about the excellent medical care for it truly flavors the choices we made. We lost one dog, and one of us will end up paying the ultimate price for that false belief.
Go north of the border for your medical care. We'd be on top of the world right now had someone had advised us to do so.