@mushroom3 they do need your permission because the grade could go down, rather than up. Obviously an overall mark that’s one below a 9 makes that very unlikely but your permission is needed regardless.
Schools have access to the breakdown of marks per paper, which we use to decide if we need to a) see the script and b) request a remark. In your DC’s case, it sounds as if the paper 1 marks are vastly different to paper 2 and therefore, this could suggest examiner error.
You’re right, a grade 8 is wonderful and he should be very proud of himself but I’d say the school is right to query the disparity between papers. My first action would be to see the script itself and decide if the mark
scheme has been applied correctly. If it hasn’t, requesting a remark is the next step. The remark will check that the work has been marked correctly; it won’t be an error adding the marks up because the school has already seen the breakdown of marks per paper.
We haven’t seen a huge different between what we predicted students and what they achieved but every year, there is a wider margin of error in English than in a less ambiguous subject, such as Maths, for example. There is a certain amount of human error expected when you’re applying a mark scheme like the ones involved in English marking.