Michael Turnbull, 44, who had taught at his comprehensive school in Devon for 16 years, was suspended in January following the incident. But yesterday Bruce Morgan, stipendiary magistrate at Newton Abbot magistrates' court, threw out the case saying if the book had made contact with the 13-year-old girl it was not deliberate. Mr Morgan said: "If this is the way the system works then the system is horribly wrong."
Teaching unions hailed the outcome as a "victory for common sense".
Mr Turnbull was charged after the girl - described by witnesses as cheeky and rude - alleged he hit her on the back of the head with a book.
Mr Morgan said Mr Turnbull could leave the court with his character intact and ordered his costs to be paid out of public funds.
He also criticised the length of time the case had taken to get to court. "How can children of 13 expect to give a detailed and accurate record of an incident which lasted 20 to 30 seconds when the case is 305 days or 44 weeks later?" he said.
Mr Morgan said that when the girl complained four days after the alleged incident, her mother had shown a "monumental error of judgement" by disrupting a lesson to confront the teacher whom she pushed.
He added: "This is a rude, badly behaved child who does not care about upsetting the class and preventing other children who may want to work."
Following the hearing, Mr Turnbull said the case represented a "scandalous waste of public funds". He added: "This fiasco has left me emotionally traumatised, socially stigmatised and professionally demoralised."
Nigel de Gruchy, general secretary of the NASUWT teaching union, believed the case should not have gone to court. "Even if true, which it was not, the alleged assault was so trivial that it should have never got beyond the bounds of the school," he said.Reuse content