Very interesting subject this, In my view we as the instructor/examiner's should be able to say that if a trainee is not upto a standard where we think that they will be safe as a driver then we should be able to decide not to test them and allow extra training before the test. But (always a but) when we are out there training especially for large companies we always have to inform the managment with there progress when they ask, personally if a trainee has not reached the standard i will usually tell them, more often than not they will always say test them anyway and see what happens. 9 times out of 10 they do fail and need more training unfortunatly they have now had a big knock to there confidence sometimes making them worse the second time round.