An academy principal who left his job after being accused of bullying and intimidating staff has been allowed to work again by the General Teaching Council for England (GTC).
A case against him collapsed last week after the disciplinary body said there was insufficient evidence to convict him.
Barrie Cooper walked away in June 2009 with a payout of around pound;45,000 from West Lakes Academy in Egremont, Cumbria, after an investigation into his behaviour found evidence of "gross misconduct" that made it impossible for him to continue in his role.
He was suspended from a previous job as headteacher of Chulmleigh Community College in north Devon, but governors kept the reason secret as part of his "exit package". Governors at West Lakes said issues at Chulmleigh had not come up during background checks.
He was suspended from West Lakes when the three main teachers' unions submitted a formal grievance letter after staff alleged they had been bullied and harassed. Teachers passed a unanimous vote of no confidence.
Mr Cooper faced charges of acting in a harassing, bullying and intimidating manner towards staff at West Lakes and not treating them with professional respect and courtesy.
His legal representative at the GTC hearing, Andrew Faux, successfully argued there was "no case to answer". The panel of teachers appointed to hear his case complained the evidence collected by the GTC was not "reliable" enough.
"The nature and quality of the GTC evidence, which goes to the heart of the GTC prosecution of Mr Cooper, is not, in the view of the committee, in a form which could justify any reliance upon it," they said.
None of the teachers who complained about Mr Cooper had prepared a witness statement, or came to the hearing to speak in person. The only evidence was interview records, but they did not have "statements of truth" attached - which add legal weight.
"In the absence of oral evidence from the teachers, particularly in the context of their not having completed any witness statements, with statements of truth attached, the committee has reached the conclusion that the evidence upon which the GTC relies is `tenuous', and that it can place no reliance upon it," the panel said.
"In the view of the committee, it was the teachers' evidence and the teachers' evidence alone which would have gone to the heart of this case; not the evidence of the process of interview, which was all the evidence the two investigators could give."
Mr Faux alleged the GTC had not collected any reliable evidence against Mr Cooper, but the panel said they did not accept that.
The GTC panel was told by consultants from Northern Education, who were called in to investigate, that Mr Cooper was repeatedly heard saying that he would "strip out" poor teachers and they would be "removed and replaced".
A GTC spokeswoman said: "GTCE hearing committees must carefully weigh the evidence in each case. In some, a committee will judge that it cannot place sufficient weight on the evidence before it can make what is a very serious decision with the potential to affect a teacher's registration."