"They've tried to point a finger at people more senior than where we found the decisions were made," Pickering said of Clinton's critics.
The Accountability and Review Board, which Pickering headed with retired Adm. Mike Mullen, the former chairman of the Joint Chiefs of Staff, did not question Clinton at length about the attacks but concluded the decisions about the consulate were made well below the secretary's level. Pickering's defense of his panel's conclusions, however, was unlikely to quiet Republicans' calls for accountability for the attacks that left four Americans dead, including an ambassador.
Pickering and Mullen's scathing report released in December found that "systematic failures and leadership and management deficiencies at senior levels" of the State Department meant that security was "inadequate for Benghazi and grossly inadequate to deal with the attack that took place."
That, however, has done little to calm Republicans' inquiry.
The House Oversight and Government Reform Committee last week heard a riveting minute-by-minute account from a former top diplomat in Libya about the Sept. 11, 2012, attacks on the diplomatic outpost in eastern Libya. Gregory Hicks, a former deputy chief of mission to Libya, detailed his phone conversations from Tripoli with Ambassador Chris Stevens, who died during the two nighttime attacks.
Hicks and two other State Department witnesses criticized the Pickering and Mullen's review. Their complaints centered on a report they consider incomplete, with individuals who weren't interviewed and a focus on the assistant secretary level and lower.
The hourslong hearing produced no major revelation but renewed interest in the attacks that happened during the lead-up to the November 2012 presidential election.
Meanwhile, the top Republican on the oversight committee wants sworn depositions with Pickering and Mullen.
Rep. Darrell Issa, R-Calif., said he would request private testimonies from both on Monday. Issa also said his oversight panel has not been provided sufficient details on the State Department review, such as a list of everyone the investigators interviewed or a full transcript of those conversations.
"We want the facts. We're entitled to the facts. The American people were effectively lied to for a period of about a month," Issa said.
Pickering, sitting next to Issa during an appearance on one Sunday show, said he wanted to appear at Wednesday's hearing, which Issa led, but was blocked.
Issa said Democrats could have invited their own witnesses, such as Pickering, but did not.
In a separate interview, Pickering said he asked, via the White House, to appear at that session. He said he could have answered many of the question lawmakers raised, such as whether U.S. military forces could have saved Americans had they been dispatched to the consulate, some 1,600 miles away from the nearest likely launching point.
"Mike Mullen, who was part of this report and indeed worked very closely with all of us and shared many of the responsibilities directly with me, made it very clear that his view as a former chairman of the Joint Chiefs of Staff that there were nothing within range that could have made a difference," Pickering said.
Even so, Republicans showed little interest in relenting to explore what happened at the consulate, what might be done to prevent future such attacks and what political calculations went into rewriting talking points the U.S. Ambassador to the United Nations, Susan Rice, used on news shows the Sunday after the attack.
A series of emails that circulated between the State Department and the CIA led to weakened - and, in some cases, wrong - language that Rice used to describe the assault during a series of five television interviews the Sunday after the attacks.
"I'd call it a cover-up," said Sen. John McCain, R-Ariz. "I would call it a cover-up in the extent that there was willful removal of information, which was obvious."
"I was surprised today that they did not probe Secretary Clinton in detail," Sen. Kelly Ayotte, R-N.H., said, of the review board.
One Republican eyeing a White House run, Sen. Rand Paul of Kentucky, told an audience in Iowa that he thinks the Benghazi attack "precludes Hillary Clinton from ever holding office."
Clinton's allies said Republicans were looking to weaken her ahead of a potential 2016 campaign.
"This has been caught up in the 2016 presidential campaign, this effort to go after Hillary Clinton," said Sen. Dick Durbin, D-Ill. "They want to bring her in because they think it's a good political show and I think that's unfortunate."
Pickering, however, declined repeated opportunities to criticize Rice's now-debunked talking points that suggested the attacks were not terrorism.
"That was not in our mandate," Pickering said. "We were looking at the security, security warnings, security capacity, those kinds of things."
Democrats similarly did little to defend the mistaken talking points.
"This is one instance where you know it was what it was," said Sen. Dianne Feinstein, the California Democrat who heads the Senate Intelligence Committee.
"There was no question this was a terrorist attack," said Rep. Adam Smith, D-Wash.
Pickering spoke with CNN's "State of the Union," NBC's "Meet the Press" and CBS' "Face the Nation." Issa and Feinstein spoke with NBC. McCain spoke to ABC's "This Week." Ayotte and Durbin were on CBS. Smith spoke to "Fox News Sunday."