It's feedback, how will you learn to do better in future groups if you can't take criticism?
Its a difference between feedback and insults. "Chair didn't even realize she was chair until the last 10 mins." Maybe I am just sensitive but that sounds like a cheap shot to me. Proper feedback could have been "Chair could have been a bit more assertive."
Feedback is one thing but it doesn't help to be an *** to someone and ridicule them.