Members of the US Congress have expressed their disappointment to Mr Chris Patten that his report on policing in Northern Ireland did not propose how to get rid of the "bad apples" in the RUC. But Mr Patten retorted that he was against engaging in a "witch-hunt".
The small number of congressmen who attended the hearing on the report also regretted that it did not recommend a ban on the use of plastic bullets and on membership of sectarian organisations by police officers.
But there was also praise for Mr Patten and Senator Maurice Hayes, who was present with him, for the work done by their commission. Fears were expressed, however, that there may be a long delay in implementing the report.
Congressman Chris Smith who chaired the hearing said later: "This lack of a vetting procedure - a way to ensure that it is indeed the `bad apples' who leave rather than cling to their seats of power and abuse - is the most troubling omission of all. It is our hope that we may learn that either the newly-recommended oversight commissioner or perhaps the new 19-member police board has been empowered with this critical vetting authority."
The "vetting of bad apples" turned out to be the most controversial aspect of the testimony of Mr Patten, which lasted just over an hour. But the exchanges were polite and there was disappointment that Mr Patten had to leave for an appointment in the White House before all the congressmen present had had a chance to question him.
He was followed by Mr Michael Finucane, son of the murdered Belfast solicitor, Mr Patrick Finucane, who told the committee it was a "glaring omission" by the Patten report that it did not deal with death threats made by RUC officers against his father and Ms Rosemary Nelson, murdered earlier this year.
Mr Patten, who at times showed emotion by jabbing his fingers on the table when denouncing the more extreme criticism of his report in British newspapers, began his testimony by some personal impressions of his time in Northern Ireland.
He described some "very difficult meetings" during the consultation process, when he met widows of murdered RUC officers and relatives of victims of loyalist gangs. One evening after such meetings "I had the longest drink I ever had in my life".
He rather nonplussed the politicians on plastic bullets by telling them that when American police officers were asked by the commission what they would do if attacked with petrol bombs, they replied: "We'd use live rounds."
Mr Patten said his report recommended more restrictive use of plastic bullets in Northern Ireland, but did not propose a complete ban because the police had still to deal with blast-bomb and petrol-bomb attacks.
Mr Patten said he knew he was treading on controversial ground with the committee over its efforts to ban funding for FBI training courses for the RUC. "It is very important that the new police service in Northern Ireland not be isolated or cut off from the rest of the world," he said.
Any foreign police force which brought together members of the RUC and the Garda, as the FBI has done, is doing a signal service to the community in Northern Ireland Mr Patten told the congressmen, who did not seem to share his views.
Congressman Ben Gilman, who is chairman of the International Committee on International Relations, said he was disappointed the Patten report did not recommend a ban on membership of sectarian associations, especially as the Chief Constable of the RUC, Sir Ronnie Flanagan, had told the House of Commons he was against such membership.
Mr Patten said it was a question of civil liberties, and police officers should not be denied the right to join orders, but their membership should be declared to the authorities. He said it was not just a question of the Orange Order but also of the Freemasons, other loyal orders and the AOH.
Senator Hayes, who was also asked if he supported a vetting process, said "we must avoid a witch-hunt" and "increasing uncertainty for the good and honourable police officers". The problem could be dealt with by retraining and the expected high turnover in the existing force as the reforms were implemented.