Avoid
What you should avoid in these situations in charging at the other parents or teachers in these situations. Usually, no child wants this sort of escalation and can even make the bullying they face even worse.
Their Experience
Make sure you are not dismissing their experience. It can be quite difficult to be told that your feelings are not valid, especially when you’ve shared your experience and become vulnerable. That’s how your child feels if they do not feel like their feelings are valid, which you can help control.