Very experienced airline instructor lost his medical, but argued that he hadn't lost his brain, and could instruct qualified pilots - who would undoubtedly be PiC - in the finer arts of instrument flying towards their I/R flt. test. No way, bureacracy has no sense of humour.
Would not happen in FAA-land.
Said ex-airline guy could instruct to his hearts content.
He could not, however, be an examiner.
FAA, far
far more practical.
But of course, you already knew this....
