Only an authorised Examiner (and the applicant) is permitted sight of the papers. Others may invigilate the exams, but only an authorised Examiner may mark and debrief the paper.
If 'schools' are in the habit of allowing anyone else to check the papers or to see the applicant's answer sheet, they had better stop such practices pronto! The CAA are, quite rightly, very hot on this!
Remember also that, if you pass the paper, you must be debriefed on the answers which were incorrect. If you are not, don't pay the fee (if there is one - I don't charge for PPL exams taken by students undertaking flying training at my RF).