When teacher Andy Drzewiecki sent a classroom bully to the head teacher he thought he was operating his primary school's zero tolerance policy on the boy.
When the child refused to go, according to Mr Drzewiecki, he took the boy by the shoulder to the door and sent him to the head teacher saying he would be following.
Next day the former weightlifter, who competed in the Moscow Olympics, found himself confronted with an allegation that he had used excessive force on the boy.
He was ordered home at once from St Mary's Tunstall, Stoke-on-Trent, and although a police investigation was dropped, Mr Drzewiecki was sacked six months later in June 2007, following a disciplinary hearing.
"I was absolutely horrified, I felt cheated and that my career was in shreds," Mr Drzewiecki said at the time.
A parent texted him a few days after the incident to say he had heard the boy and his friends boasting about the incident.
Mr Adrian Chell told BBC Radio 4's File On 4 programme: "I heard the child bragging about how he got rid of Mr Drzewiecki and he was with two or three other children who were laughing and joking that they had got their story straight and he [Mr Drzewiecki] wouldn't be coming back."
Mr Drzewiecki alleges the school disciplinary hearing downplayed this evidence and he was amazed that the head teacher, who was also a witness to a key event, took charge of the school investigation.
Last year an employment tribunal, after five day days of hearings, ruled that Mr Drzewiecki's dismissal had been "thoroughly unfair".
It issued a judgement which noted the boy's violent record and criticised the head teacher's failure to speak to key witnesses such as Mr Chell.
The tribunal ruled that the investigation had been "thoroughly inadequate" and that the head teacher, "by no means could be considered an independent investigator - she was involved in one of the very incidents that led to the claimant's dismissal".
Mr Drzewiecki finally won compensation, but he told the BBC the incident made it extremely difficult for him to work again as a primary teacher.
Jenni Watson, an advocate who represented Mr Drzewiecki and has acted for other teachers, said his experience was typical of teachers who face accusations from pupils.
"The investigation of Andy Drzewiecki's matter was like most I deal with, inadequate and begun from the wrong premise - the education authority and the head teacher had a view of his guilt before the investigation began and what they were trying to do was to collect evidence of that guilt so they could present a case to the governors," she said.
The school's head teacher Mrs Gill James would not be interviewed but issued a statement saying she and the school governors had contacted Stoke-on-Trent local authority immediately after the incident.
Mrs James added: "All of the subsequent procedures were undertaken on the specific advice of that department."
The council refused an interview, but said it had followed disciplinary procedures appropriately.
Cases like Mr Drzewiecki's are a blight on the teaching profession, according to teaching union NASUWT.
The union blames the way schools and councils are trying to toughen their child-protection regimes.
Chris Keates, the union's general secretary, said about 800 of its members every year were subject to complaints, often based on claims they had used excessive force.
"In the vast majority of cases, it's not been anything to do with abuse, it's been teachers trying to manage a difficult situation," she said.
Even if the claims are found to be bogus and the teacher is exonerated, the investigation and the disciplinary action might well remain on their record.
The Department for Children, Schools and Families rejected an interview request but said the government had been working to improve the way allegations were handled to both protect children and ensure fair treatment for teachers.
It said the department was looking at whether guidance on handling allegations should be amended to make clear that allegations which are found to be untrue "do not need to be included in teachers' references".
A government minister recently told MPs that as many as 2,500 teachers a year faced allegations of using excessive force.
Barry Sheerman MP, who chairs the Commons Select Committee on Children, Schools and Families, is alarmed at the figure and the traumatic impact on teachers.
He told File On 4, "That's very concerning because if you add allegations of a sexual nature and other miscellaneous categories it's a lot of cases and a lot of anguish for many teachers."
Mr Sheerman says his committee is now planning to hold an investigation.
He added: "It's costing the taxpayer a great deal of money, it's disrupting the life of schools in a way that should happen.
"I want to find out if we can cut through this nonsense, to get justice takes a long time and the onus seems to be on proving your innocence."