I'm very sad your teacher did this. A good teacher is not an authority. Maybe your teacher should hunting for another job, e.g. a king?
You shoud not have told your teacher that s/he was wrong. S/he didn't deserver your correction. Just let s/he believe hir wrong idea, and let every other laught at hir for hir life time!
-- weakish
Thanks for you comments but I wasn't being literal. I wasn't
actually that student, I just could have been very
easily ... 
-- Adam.