Can I laugh too? Don't worry I won't

The teacher should have asked me if I understood the mathematics being that I used to have others correct.

I think this situation of your happened for a reason which was a lesson for you and your teacher too. It's not good to draw conclusions about something when you're not sure. Such actions can bring conflicts which is not usually healthy in a learning environment.

Trainers and learners should always try to be out spoken too so as not to embarrassed in anyway. Nice write up