"I think you get extra marks for memorising in exams. My son (here I go again) memorised all his three pieces in his Grade 5 exam recently and it could well have helped towards his 100% marks in each one of them. It also helped him to play them really confidently as they were 'in his blood' so to speak.
Please excuse the constant unsavoury bragging about my son's exam - I'm partly (mostly) Jewish therefore have every excuse."
I don't have any problem with bragging. I'm happy to brag about my daughter who got 143 for Grade 8 violin.
However, alarm bells ring when I hear of someone getting full marks for all three pieces (she didn't get full marks for any of hers). For me, "perfection" is a very, very strong and unequivocal term. It means there was no tiny detail that could have been any better. In all the years I've been performing as a pianist and flute player I can remember only one single occasions when absolutely everything went exactly as we had planned it (I was accompanying my flute teacher in a sonata by the 18th century composer Leonardo Vinci, not to be confused with the more famous Leonardo da Vinci). Last year a candidate I was accompanying, an adult who was already very proficient on another instrument, got full marks for one of his Grade 4 trombone pieces, and I really felt he deserved it. The playing was both technically accomplished and stylish.
Within the last couple of years I've heard of a young GSMD flute candidate being awarded full marks for all three pieces. The really alarming thing about that one was that she had come out of the exam quite dissatisfied herself with one of them. To my mind that devalued the whole system. I also remember a previous occasion, not an exam but a festival, where an adjudicator awarded full marks to an exceptionally good performance which I knew wasn't perfect. It really tarnished the occasion for me and for the performers, who also knew it wasn't perfect, and we despised the adjucator for apparently not knowing the difference between exceptionally good and perfect.