Kindergarten son in an unruly class

A.

My five year old started a new school last week and every day he tells me daily how it was a horrible day because everyone keeps talking when the teacher is talking and then she yells and tells them they're breaking her heart by being so bad.

My son loves school and I only heard good things from him about any other class he has been in. I'm worried that this is impeding his learning experience or will influence him badly.

I feel for the teacher. I want to make sure my son isn't contributing to the problem. Is her class too big? Are there a couple students who need better discipline? Should I talk to her or the school and what should I say?