Wow - as another teacher who also works at a school with the online grades, I know well the double edged sword part of the situation, but that is un-excusable.
We have a policy about how often we have to post grades and how quickly we have to return grades to students. And, yes, we would contact parents after just a few missed assignments, not 12! If it was the case that the teacher had gotten behind with marking and for some reason didn't know that she was missing that many assignments, the teacher should have immediately contacted you about them.
