I just looked at her and finally said that if I had ever done anything like that, I wouldn't have had a job. As it turns out, the teacher on the video doesn't have a job either.
Every teacher will run into a student that pushes them to the edge. The teacher has to make sure that the student doesn't push them over that edge. Every teacher needs to remember that a school is a miniature representation of our society. There are good guys and bad guys. Some students will go on to great things and some will become criminals (if they aren't already). But regardless of what they do or say, it is the teacher's job to remain professional.
Usually when a student has pushed a teacher to the edge, it is the result of a series of events that have taken place over a period of time. It's not usually just the one thing the student did. When a teacher sees this taking place, he or she should get help. Contact the child's parents, the principals, the counselors, and the student's other teachers. Take care of the problem, before it reaches the point where any kind of physical violence takes place. It may be that the teacher actually needs counseling, mentoring, or refresher courses in discipline. Remaining professional means getting help when you need it.