Insurance emergency evacuation (not to departure city)

Cross posted in RTW, Mexico and Cambodia branches.
I read the FAQ - "Insurance - the great debate!", and the article link to the Australian Medical Journal Article. The point about insurance policies not covering emergency evacuation to a hospital with an appropriate standard of care sounds pretty scary and shocking! Is this true, and common for insurance policies?

I'm shopping for an insurance policy to cover a 33 day trip to Cambodia & Australia, and will be going to Mexico for 9 days next April. (I'm Canadian btw.) Will be partaking in "risky" sports like scuba diving (certified open water diver), surfing, etc. I read the fine print of a few insurance policies (RBC insurance, and Travel Guard) and it seems that they only cover emergency ground ambulance and emergency evacuation to my departure city (which would be back home in Canada).

However, if something were to happen in Cambodia and I needed service to evacuate to a hospital that would offer better standard of care, it sounds like this wouldn't be covered, and I even tried phoning Travel Guard, and the girl on the other end re-read the fine print, and basically couldn't confirm that this would be covered, in other words...?

So, then I'm left to wonder which insurance companies should I look at? It sounds like from the FAQ that STA and World Nomads is a good one though I guess pricier! I'm still shocked that this is excluded in most insurance policies! I'm driven to the point of wanting to do something more about this, though I'm not sure who regulates insurance policies.

Also, is emergency evacuation to another hospital better something I need to think about when traveling to Mexico (Cancun)? Or are Cancun hospitals pretty much world class?