A co-worker recently met with her son's teacher about some petty BS and was saying she felt silly about it but it was important to her sone. I observed that it was always best to make it known that you were aware of everything that went on in the classroom. First, you get more respect from teachers who are used to dealing with apathetic parebts. Second, it is good for them to know you will not back off if you feel you are right.
Always worked for me.
Unfortunately, some teachers and administrators assume they have a free hand in dealing a child. And crap like this happens.
Although it seems these are involved parents. Good for them.