tdracer, The delegated examining system worked well in Britain back in the 1980s when I was a flight training manager (I have no idea what it is like now). And I always emphasised to the instructors that when, they were conducting pilot tests, they were working on behalf of the CAA and, by extension, the safety of the travelling public.
Equally, when we did CofA air tests on aircraft, we were acting on behalf of the ARB and later the CAA.
Delegation works well so long as the integrity of the process is maintained.