The text states just that and this is what I am trying to explain here, that the use of the word shall is as good as using must, if all other factors stand.
This is why I asked if "shall" and "may" are one and the same in the eyes of the law, still unanswered but I see you have used "shall/must" in your text which now gives me hope.
The eligibility in the text is with respect to the term in office, such that the CAG must be re-appointed again for the next 5 years BUT if she/he has already served 10 years, then she/he is not eligible for re-appointment.
True, only if the CAG is ineligible.
False, if the CAG is eligible.
It is as good as a must, should all other factors remain valid. 2 + 2 and 4 are one and the same. It should be interpreted as it is and not as you would want it to be.
Now please answer my question: is the use of "shall" and "may" one and the same in the eyes of the law with respect to our argument here? If not, then there is no point of us debating, it's over.