@ngwono,
So, this is not the first time he is sitting sec 3 and sec 4? I see like that is the only way he could be having such a combination of subjects.
Lakini Ngwono, It appears you have overlooked one thing. Have you asked him for the result slip? If you haven't seen it, You may need to have a look at it or you will appear as very ignorant when you are talking to KASNEB.
Now if he had in fact booked for sec three, something will be indicated on the result slip. He was either referred, or did not show up. Now every time you sit a KASNEB paper, you sign on a certain sheet. I am sure if there is a dispute,KASNEB can produce this sheet. All the best