Mr Owen, a former deputy head teacher, allegedly told one London primary headteacher "to expect a Rolls-Royce of inspection" that would be "no consolation to those crushed beneath the wheels". He led a team that failed 15 per cent of the schools it inspected, against a national average of 2 per cent.
John Harries, former headteacher of Hillbrook primary school in south London, alleged that Mr Owen drove him to a nervous breakdown.
Mr Woodhead, who sacked the inspector after complaints from 10 schools backed by teachers' unions, sent a private, handwritten letter to Mr Owen, offering to "oil the wheels" for future appointments. Heads accused Mr Woodhead of "cronyism" yesterday.
An unrepentant Mr Owen said the dispute highlighted the debate over how tough inspections should be. Most inspectors, he said, "pulled their punches". But the purpose was to change schools. "I agree 100 per cent with Chris Woodhead that schools need independent, objective inspections."
He ended up inspecting so many schools, he said, because "many inspectors fight shy of inspecting difficult schools".
Mr Woodhead's letter says: "I found the decision to de- register you the hardest I have had to take as Her Majesty's Inspector of Schools. There may be nothing I can do to help with the future but if there ever is I will do it. Don't hesitate to contact me, if you think I might be able to oil the wheels."
John Dunford, general secretary of the Secondary Heads Association, said: "This is an entirely wrong sort of patronage and the chief inspector should keep well clear of it. It's a bad example of cronyism. We don't want this man inspecting schools ever again."
He said the letter raised wider issues about inspection. At present, Mr Woodhead's Office for Standards in Education (Ofsted) appoints a complaints adjudicator who cannot overturn the results of inspections. Mr Dunford said there should be an independent complaints machinery.
A spokesman for Ofsted said: "For a long time, despite a number of complaints, we continued to have confidence in Mr Owen's judgement.
"He was finally dismissed for poor management of one particular inspection where he did not perform as one would expect. That doesn't stop people having sympathy for somebody who has lost his livelihood."