C.C.
I guess without being there, it's a little hard to tell if the teacher did anything objectionable or not. Did she yank on his arm, or leave bruises? I will sometimes grab my 8-year old's arm when we're crossing the street, but I'm not being rough with her, I'm just directing her on where to go. What exactly did she say to him that embarrassed him? Was she ridiculing him, or was it that just being in front of his classmates was embarrassing when he would rather have been sitting in his chair? Those details make a difference. If she was not rough with him and did not ridicule him, then I'd tell him to pay better attention in class. If she was rough with him and/or ridiculed him, then I'd raise hell with the principal. It's hard to tell, based on the information you've provided, which route to take because the details are sketchy and mostly based on hearsay.