Shocked at the statistics about only one in six being correct - both my DS's got their predicted grades, for one that was enough for his chosen degree, for the other he changed his plans anyway and reapplied a year later with the required grades for Durham and they still took 4 months to make him an unconditional offer. I agree Exeter are barking mad with their AAA requirement for medicine; but they were like that with English a few years ago, saying initially AAA then making AAA offers to applicants - several of whom had AAA offers from Oxford - which made a mockery of the whole thing.
HYMS at open day said they would absolutely not consider below AAA, Liverpool said apply even if you are predicted AAB! Maybe some medical schools would also take a high UKCAT score and high interview score into consideration before deciding whether to accept someone who missed a grade?