Hillbrook primary school in south London was only 250 metres from home, so when our two sons reached school age it seemed the obvious choice. We had heard good things about its nursery school, less complimentary comments about the school itself.

But we were determined to educate our children locally in the state sector. It was to be the beginning of a long disillusionment that ended only when Geoffrey Owen, the so-called inspector from hell, produced his OFSTED report that failed the school and drove the head John Harries to contemplate suicide.

Shortly after we became part of the school community, Hillbrook went grant-maintained, urged on by Mr Harries, and the governors. Worries that this would isolate it from the support of its local authority, Wandsworth, were brushed aside by the ideological commitment of the majority of its governing body and the zeal of its head.

I joined the governors shortly afterwards while my wife began reviving a comatose PTA. After attaining GM status, resources ceased to be a problem: in the first year, pound;70,000 went on books and equipment.

But attainment was a different story. It quickly became clear that many pupils were leaving school illiterate and innumerate. Don’t worry, I was told, your sons will be OK. I knew that: they are fortunate enough to have well-educated and motivated parents. What about the other pupils, some of whom don’t? We’re doing the best we can with the children we’ve got, I was told repeatedly.

It is not easy to decide that your children’s school is inadequate. Art and music were encouraged and the football team excelled, but academic basics were poor.

Far more disheartening was the reluctance of most governors and teachers to recognise this. Suggestions that times tables might help numeracy were countered with a shrug.

The school was reluctant to adjust to the changing educational environment. In Wandsworth, secondary-school entrance exams or aptitude tests were becoming the norm. But there was reluctance to offer Hillbrook pupils practice for such a potentially traumatic experience. The head didn’t agree with entrance exams (who did?) and that precluded any preparation.

A suggestion that a modicum of homework should be introduced at the top of the school to prepare pupils for secondary education was dismissed.

There was a lack of objective information about how the school was performing academically. But collecting it was resisted, and such resistance didn’t just apply to the academic. An after-school club? The headteacher was opposed, and allocated the obvious space for it to other purposes. The head was also opposed to a Christian assembly in an ethnically-diverse school. Sadly, most of the governors were reluctant to contest these views.

Their reluctance was understandable. Mr Harries made it clear that criticism of his school was unwelcome and reacted to it with barely-concealed hostility. The PTA was warned off discussing discipline and bullying policy, though it eventually insisted.

It was in this context that Mr Owen’s forthcoming OFSTED inspection was announced, an announcement that provoked months of preparation. At this time, despairing at the school’s lack of ambition, and with my second son about to enter it, I sent both to another state school nearby. I remained on the governing body to await Mr Owen’s report.

Its results clearly shocked the head, his teachers and some of the governors. Some of us were less surprised, though no one expected the requirement of special measures. Mr Harries criticised and challenged the findings immediately.

Less was said initially about the conduct of the inspection. The inspector’s contact with parents had been courteous and straightforward. He delivered his bad news to the governing body plainly but sympathetically.

But it was clear Mr Harries took the criticism personally. He left school on the evening of the inspector’s report and did not return for some weeks. They were not easy times for the deputy head, the staff or the governors. Even so Mr Harries was offered the opportunity to lead the school out of its difficulties. His breakdown intervened.

So did this amount to condemnation of the inspection? Not in my view. The school was complacent: before inspection, a teacher had suggested that staff had the right to be “smug” about its achievements. Academic achievement was low and expectations lower. It was resistant to changing education policies. Sadly, much of this stemmed from its leadership.

I am made more certain of this conclusion for two reasons. The contrast with my sons’ new school could not be greater. And Hillbrook’s subsequent performance has improved. With different leadership, many new teachers and a radically-changed governing body, the school is clawing its way back.

Would this have happened without the shock of inspection ? I doubt it. Without it the school would probably have gone on failing its pupils and, worse still, probably not realised it.

There are also broader lessons here. Whatever the general value of OFSTED inspections they are crucial in GM schools - and the foundation schools which will replace them. It cannot be taken for granted that governing bodies will have the knowledge or experience to understand when a school is falling below an acceptable standard. And any governor would be understandably reluctant to challenge the strongly held view of a headteacher. Governors need the objective input of education experts.

But there is also a further question. A former colleague on the governing body has moved to Liverpool. He wrote to me recently to say that the school his child now attends is not as good as Hillbrook. Mr Harries believes he fell foul of a particularly harsh inspector. Given another inspector and on another day, the argument goes, Hillbrook would have been given a clean bill of health.

It would be appalling to think that this was the case. But now OFSTED has added to that impression by de-registering Mr Owen. I believe Mr Owen’s judgement was right, his demonisation wrong. But if schools and their headteachers are to be subjected to harsh judgments and sometimes be shown the red card, OFSTED needs to counter any notion that the school playing field is uneven.

David Jordan is editor of BBC1‘s On the Record. He was a parent-governor at Hillbrook School at the time of its inspection.