U.K. teacher Peter Harvey on Thursday was found not guilty of attempting to murder a pupil and cleared of causing grievous bodily harm with intent to a 14-year-old student he attacked with a dumb-bell.
The jury at Nottingham Crown Court in central England took less than two hours to clear father-of-two Harvey.
The court heard how some students were planning to taunt the physics teacher so his reaction could be caught on camera and passed around students.
The 50-year-old slammed the weight into the 14-year-old's head while shouting "die, die, die" after the youth told him to "f*** off."
Harvey's lawyer argued that the teacher was in such a state when he battered the boy, a known trouble-maker, he could not have intended to kill or seriously harm him.
Harvey, who chose not to give evidence, had admitted causing grievous bodily harm without intent following the incident at Saints' Roman Catholic School in Mansfield in July 2009.
The judge said he would not send the teacher to jail for grievous bodily harm which he had admitted because he spent eight months on remand.
Judge Michael Stokes QC said "common sense" had prevailed.
"These are not easy cases and it's plainly in the public interest where an event of this nature takes place in a school that the jury representing the public should consider the level of guilt," he said.