Under those circumstances, if you are the ship's Doc and a man comes to you with chest pains, and has possibly had a heart attack, do you kick him off the ship and into the incompetent, unskilled and ill equipped hands of third world medicine, or do you treat him on board?
If a person comes to the Dr. with something they believe they can treat, they'll most certainly treat it. So, the argument isn't valid.
And to assume an entire country, even third world, doesn't have sanitary medical facilities is somewhat naive. No question they likely won't be up to North American standards, but to be fair, in many cases, neither are the doctors working on cruise ships. And neither do they have more than the most very basic diagnostic equiptment available to them.
You definitely SHOULD hope you or your family members don't have a real emergency on a cruise, because they are definitely no better equipped to handle them than is third world hospital.
As I've said before, ships, including Carnival ships have diverted to different ports to get their passengers medical care. I've been onboard when the ship rushed to a meeting point with coast card to medivac emergency cases. These ships are not capable of being floating hospitals. Might be dad, but it's true.
Thankfully the man in this case was not critical, and appears to be alright.
It easily could have turned out much worse