This is a telling story. My wife was a teacher. She would no more go back to it than I would become a spin doctor for New Labour. Why? She, and all her friends who were teachers, don't think it's reasonable that, in order to earn an honest living, they should have to put up with verbal and physical abuse from pupils and (as this article shows) sometimes parents as well.
We libertarians are assumed to be close to anarchists. That's not true. We believe in full enforcement of as few laws as are consistent with public safety and good order. The spurious "right" of the parents of disruptive pupils, or parents who are themselves violent or abusive, to have their children educated is a nonsense. As a wealthy society we can be proud that we provide - through taxation - state education for all. But citizens who abuse that provision should lose it - at the discretion of the head teacher responsible for the performance of that school. If they don't like it, then let them persuade another head teacher that they have brought their offspring under control, or let them pay someone else to educate them.
The "rights culture" in Britain is what gives the monsters of the underclass the impression they can behave as this article describes. A "freedoms culture" would be much better. The freedom to send your child to school to learn. The freedom of the school to expel that child if he or she disrupts the education of others. And the right of children, parents and teachers to expect to live their lives free of physical or psychological abuse - a right enforced by police released from bureaucratic fiddle-the-crime-figures work for the purpose.
BBC NEWS Education Head teachers complain of abuse