(CNSNews.com) - Thomas Pickering, the 81-year-old retired diplomat who headed the State Department's investigation into the terror attacks in Benghazi, told CBS's "Face the Nation" Sunday that he didn't believe it was necessary to ask then-Secretary of State Hillary Clinton any questions, because "we had questioned people who had attended meetings with her."
Pickering said the Accountability Review Board, which he headed, already knew "where the responsibility rested," because Clinton "had already stated on a number of occasions she accepted, as a result of her job, the full responsibility."
Moreover, Pickering said he sees no reason to question Clinton now: "I don't think that there was anything there that we didn't know."
Asked if the ARB let people off the hook, as State Department whistleblower Greg Hicks told congressional investigators last week, Pickering said no: "I don't believe so," he told Bob Schieffer.
"They've tried to point the finger at people more senior than where we found the decisions were made. The decisions were made and reviewed at the level that we fixed responsibility for failures of performance. Those people were named in the report. Two of the four that we felt failed in their performance were, under our recommendation, relieved of their jobs."
Pickering noted that one of the people named by whistleblowers was Undersecretary of State Patrick Kennedy: "People have pointed to him. We believe, in fact, that while he made a significant decision to keep the (Benghazi) post open, he was not a security specialist. He was not engaged in a daily review of the decision-making that took place, that we felt in some cases was seriously flawed. And as a result, we don't believe it went higher."
Pickering indicated that the ARB spoke to Clinton and other high-ranking State Department officials simply to brief them on the review board's findings:
"We interviewed Secretary Clinton. We interviewed secretary -- Deputy Secretary Burns, and Deputy Secretary Nides. We briefed them on the report. We told them where we were. It was near the end. We had plenty of opportunity, had we felt it was necessary, all five of us, to ask them questions. We didn't believe that was necessary. And I don't see any reason to do so now."
Pickering also said the review board did not record and transcribe its interviews with State Department officials.
Asked why not by a slightly incredulous Schieffer, Pickering said, "Because we didn't feel that it was necessary for to us get the essential elements of information down." The ARB relied on "notes" instead.
Pickering said his review board had no interest in the controversial aftermath of the Benghazi attacks -- changes made to the "talking points," which Ambassador Susan Rice relied upon to give the false impression that what happened in Benghazi began as the result of a spontaneous protest in Egypt over an obscure anti-Muslim video:
"I just don't understand why you wouldn't have checked into that as part of this investigation," Schieffer said to Pickering.
"Because the talking points came after the fact," Pickering responded. "They made no difference at what happened at Benghazi. They related to how and in what way people were explaining to the Congress and the American public. The question of culpability, which is hinted at in the recitation of the talking points, was specifically reserved under our criminal statutes for the FBI. They have that responsibility. They were concurrently reviewing that question -- who did this? Why did they do it? Who was responsible? Were there criminal charges under U.S. law possible?"
According to Pickering, the ARB "had a different set of responsibilities, and we had a different set of questions we had to address."
Pickering said the ARB was asked to look "at five questions, all of which had to do with security, with the adequacy of security, with the preparation of security, with intelligence, and whether anyone breached their duties. That was, in effect, our mandate.
"At the time and still now, I find it hard to see how the talking points issues relate to the security at the Benghazi mission."
Rep. Darrell Issa, chair of the House Oversight and Government Reform Committee, has said that "specific parts" of the ARB report were either "incomplete, or in fact, are just wrong."
Speaking to NBC's "Meet the Press" on Sunday, Issa said on Monday, he'll send Pickering a request for a deposition: "We're going to want to go through, at length, ow the ARB reached its conclusions, who they had interviewed..."
"We believe it was insufficient. We believe that it's likely that they did not interview all the people. We have one witness who said I wanted to be interviewed, and I wasn't."