Involved in recruitment in Europe for a few years now, it's a well to have ICAO English Levels, but I had to reject applicants more than once for their poor English communication skills. It looks good on paper, but some pilots with even level 6 in Europe, still can't speak English properly, let alone in an Emergency situation. How they get their certificates is another issue...
A native speaker or good command of English language can find different ways of passing the message across. One can easily and quickly rephrase to make oneself understood.
I had once to declare a medical emergency on short finals, and ATC mumbled that their were not informed earlier! Told them I tell you what I know when I know it, and when it's relevant, and it was not before that very moment, keeping up to date with the cabin.
With such a short time on finals, I cannot say I would've done any better.
I strongly disagree with the controller's attitude. What if it had been a new pilot flying solo? You think they would have had a perfect phraseology? Have you ever heard a Korean Airlines or Chinese aircraft in EU or US airspace? Their way of speaking is hard to understand, and it would be far from standard phraseology.
Flex