90% of people would be fine with it too, maybe more. Unfortunately, it would be VERY easy to catch someone in a very bad state, and make it even worse. Without the context of what sort of person they are, and what they are currently in for, it's FAR more likely to run into someone who wouldn't see the funny side.
Don't get me wrong, it could be hilarious. E.g. the guy who did the same at a nursing home, where he also lived. The heart attack induced was just an unfortunate outcome that put it in the news.
If you want to get extremely pedantic, "Queens English" was defined as the reference. The rich toffs of the British empire got annoyed at their servants having various accents, and either being hard to understand, or mishearing them.
In this case however, it was meant as a local accent, so none noticeable.