Mid year exam

It is mid year examination for students in my school. My paper was on the second day of exam. I thought I wouldn't be nervous, but.. I was a little bit worried that they couldn't do well. Nonetheless, I have successfully marked their papers and the results were almost satisfying if not for a fact that there are 3 Jaid Jiddan and 1 Jaid in 5 Abyadh. 5 Ahmar on the other hand, got Mumtaz all 23 of them. I couldn't take credit for that because I only took over their class during revision week, while 5 Abyadh I took over their class about a month plus before exam. I can't help but feel that part of the problem is that I wasn't successful in making them clever-er (if there is such word!) which also could mean I'm not a good teacher.. Whatever it is, I'm a bit worried that their 'real' teacher would complain although I know she wouldn't because she is very kind...