Is it permissible for a student not to inform the teacher about an increase of half a mark in their test grade?

The fatwa does not explain how it ruled that the teacher was wrong for adding half a degree to the student, because the reference for deserving grades is the teacher's evaluation, not the student's evaluation of his own work. If it is proven that the teacher made a mistake in estimating the grade and added more than what was deserved, the teacher should be alerted.