The report led the State Department to relieve three employees of their posts -- while a fourth resigned -- because of "systemic failures and leadership deficiencies at senior levels in securing the compound."
The departing staffers are still on administrative leave, however, meaning they are still State department employees.
While most senators took time out of the two-and-half-hour-long hearing to praise Clinton's tenure at the State Department, others came down hard on her.
Sen. Rand Paul, R-Texas, did not shy away from placing full responsibility on Clinton's shoulders.
"I think that ultimately with your leaving you accepted culpability for the worst tragedy since 9/11," Paul told the secretary. "Had I been president at the time and I found that you did not read the cables from Benghazi, you did not read the cables from Ambassador Stevens, I would have relieved you of your post. I think it's inexcusable."
Clinton said that was the reason her department turned to the Accountability Review Board.
"The reason we put into effect an accountability review board is to take it out of the heat of politics and partisanship and accusation, and to put it in the hands of people who have no stake in the outcome," Clinton told the committee.
The secretary herself remained energized throughout the hearing. Indeed, Sen. John McCain, R-Ariz. called her "as combative as ever" before launching into his own attack on Clinton, who had testified that the motivation for the attack in Benghazi shouldn't matter at this point.
"Why do we care?" McCain asked. "Because if the classified information had been included, it gives an entirely different version of events to the American people.
"So here we are, four months later, and we still don't have the basic information."
Clinton ripped into Sen. Ron Johnson, R-Wis., for asking a similar question.
"With all due respect, we had four dead Americans. Was it because of a protest or was it because of guys out for a walk who decided they'd go kill Americans," she said, gesturing sharply with her hands to emphasize each sentence. "What difference at this point does it make? It is our job to figure out what happened."
Clinton testified briefly before the Senate less than two weeks after the attack, an appearance that received considerable criticism from conservatives.
McCain said Clinton told the Senate "nothing" at that hearing.
"We were told absolutely nothing, all because it's an investigation going on," McCain said on the Senate floor Sept. 21, 2012.
Sen. Robert Menendez, D-N.J., is presiding over the hearing on the Senate side, in place of out-going committee chair Sen. John Kerry, D-Mass., whom President Obama has nominated to take over Clinton's position as secretary of State.
Ed Royce, R-Calif., chairman of the House Foreign Affairs Committee, is presiding over the afternoon hearing.
This won't be Clinton's last trip to Capitol Hill. At the end of the Senate hearing, Menendez said that Clinton would be one of the people introducing Sen. Kerry at his confirmation hearing before the Foreign Relations Committee Thursday.
ABC News' Dana Hughes contributed to this report.