My son said the same but more exagerrated: 20+ students got 97% in Chinese subject in 2E. I think he might not count well.
He also said the teacher said he won't give the exam papers back no ...
The computer subject does not count as main subjects and over 85 is already an A.
He is just asking himself too much. Don't worry. See last time he can still do it even though u were so angry with him. He should give you a satisfactory result this time.