Calm down, as long as your conscience is clear, nothing will
bring you down.
Sometimes, I've got to kowtow to the Singapore teachers here. They
know such things will happen. So what they do is, prepare an
attendance list, ask them collect the tutorials and sign their
names.
Whoever complains that he didn't receive, shall receive a nice
present from the teacher. 
Actually, how nice
can the present get? They don't have the powers, only can sabo you
nia.