A headmaster accused of grabbing a 14-year-old boy and ripping his hoodie has been cleared of assault.
Aidan Smith lawfully restrained the boy at a leisure centre last year after fearing he was about to get involved in a fight, a district judge ruled.
It was alleged Mr Smith was so enraged he was "spitting from his mouth" and threw his sunglasses to the ground.
But the judge ruled Mr Smith, from Long Eaton, Derbyshire, was blameless and acted to protect others.
The incident happened last year away from the Staffordshire school where Mr Smith worked at the time.
He was also cleared of criminal damage in connection to the ripped hoodie of the boy, who cannot be named because of his age.
The boy, who was uninjured in the incident, told the court on Monday that Mr Smith wrongly believed he was being mocked.
But district judge Kevin Grego said he did not believe the boy's claim about Mr Smith throwing his sunglasses on the floor, adding: "Whatever his behaviour was about, [the boy] was presenting a risk of injury to himself and others.
He ordered Mr Smith's defence case cost be met by the state.
Mr Smith told the court he put his arm out to stop the boy and then "closed his hand" on the hoodie.
"I thought I was restraining him... so that he didn't run away and carry on being unsafe.
"He thrashed down at my arm a few times and then I heard the hooded top rip and I let go."