Even if he is not consistent,

so what? Does he worth of a law suit for being inconsistent? Come on! His act is not against any law, but just an error or mistake. OK, guys!


READ the LAWS!
The court is serving those who are hurt, injured, humiated, damaged, etc by those who had done something to them beyond the law.

Your poor professor just gave you an incorrect score, even if he gave you an zero by mistake, he still has chance to correct it. Which federal, state or local laws says that the professor must not make mistake?