HMI was responsible for driving through Higher Still without listening to teachers, Mike Russell, the SNP's shadow education spokesman, brusquely told the senior chief inspector of schools.
Douglas Osler's version of events was "astonishingly manipulative", Mr Russell said. Evidence to the committee showed "substantial disquiet over a lengthy period of time". Yet inspectors only chose to heed the voices they wanted to listen to.
Mr Osler replied that there had been more dialogue with teachers on Higher Still than there had been with Standard grade and the 5-14 programme, with more than 240 consultations. Post-16 reforms were by their nature more complex.
"I would suggest to you HMI has no reason at all to pick a programme such as Higher Still and decide it is the role of the Inspectorate to push it through," he said. "Successive education ministers asked the Inspectorate to co-ordinate the implementation of Higher Still. That was done through the strategy group, the implementation group and eventually the liaison group, all of which had representatives of all the main stakeholders.
Headded: "HMI had no vested interest in pursuing this programme. This programme was the result of reports ministers initiated and which were consulted on." As policy advisers, inspectors turned information into advice for civil servants who submitted advice to ministers.
Mr Russell riposted: "It is a closed circle, Mr Osler. When the history of this is written, that closed circle, that conflict of interest within the Inspectorate, is a major factor in what took place this year."
Mr Osler replied: "The people who decide about whether or not there should be policy are ministers. Since I have occupied a senior position in the Inspectorate, I have worked with seven education ministers, four secretary of states and one first minister. I never known any member of the Inspectorate to be allowed to make policy decisions. That would be entirely inappropriate."
Mr Russell said it was time, as the unions believed, to break HMI's link between "generator and policeman" of policy.
"You are back to saying we generate policy. But all the facts show we do not generate policy," Mr Osler said.