I was teaching my first class of the day yesterday when behind me I heard a student on a cell phone and my coteacher, a Japanese language teacher with pretty limited English, shouting at him to get off the phone immediately (from what I understood in Korean). When the student was done making his call, the teacher scolded the student and they both left the class in a hurry. I was at the front of the class with and never saw what happened between the teacher and student. The other students in class told me that the teacher asked the student to be quiet then punched the student. The student then got up, went to his locked, grabbed his phone, and called the police on her. The remainder of class was continually interrupted by teachers coming into class and asking students what happened.
I was later called down to the main office by my actual coteacher and was asked what happened during my class. I told her I wasn't sure because I was facing away from the teacher and student when the incident happened. She then told me the school felt this was slightly my fault for having students work in groups instead of on their own and wanted me to no longer have students do group work in my classes.
Has anyone ever had something like this happen in their school before?