There isn't enough background to really say. From what the video depicts, the teacher wasn't being nice to that girl, and seemed like she lost her temper. It also sounds like the girl was just messing around on purpose to get out of having to do her school work. What I'm saying is it sounds like this isn't the first time this child tried to manipulate the situation in her favor and the teacher knows the student is smarter than what she is displaying and there fore disrupting the lesson. The teacher didn't handle it well, that's for sure, but it's not disturbing. Also no one is asking what's the other side of the story?