On Thursday, House Republicans continued to ask questions about Hillary Clinton in connection with the attack on the U.S. facility in Benghazi.

This time, in questioning the State Department's review of the attack at a House Oversight and Government Reform Committee hearing, they asked why Clinton wasn't interviewed and whether the report had been politicized.

"How could you look at everything when you don't even bother to interview the person who is ultimately responsible for what happens at the State Department?" Rep. Trey Gowdy, R-S.C., asked Adm. Mike Mullen, the former Joint Chiefs of Staff chairman who headed the Accountability Review Board that produced the Benghazi report.

Mullen appeared along with retired ambassador and former U.S. ambassador to the U.N. Thomas Pickering, who co-chaired the review board, to answer questions about their 39-page report, which identified four State Dept. employees whose unsatisfactory performance contributed to a subpar security presence in Benghazi. The report resulted in their removal from duty under Clinton, and their eventual reassignment under current Secretary of State John Kerry.

Multiple Republican lawmakers questioned Mullen and Pickering on why Clinton wasn't interviewed for the report.

Pickering said that, by the time the ARB worked up the chain of command to Clinton and other high-ranking State Dept. officials, it was clear who was responsible for mistakes before the Benghazi attack.

"At the time that we got to them, as it was with Secretary Clinton, we had very clear evidence, full and complete to our information, that the authority, the responsibility, the accountability, rested with the people we identified," Pickering said.

Clinton appointed four of the five review-board members, and Republicans raised the notion that the process may have been politically tainted and lacked true independence from the State Dept.

"It looks like sort of an inside job of investigation," said Rep. John Mica, R-Fla.

"The ARB's structure, along with the State Department culture, raises questions about the extent to which it can be independent," Chairman Darrell Issa, R-Calif., said in his opening statement.

Clinton was required to appoint the ARB members, according to a State Dept. official, and Mullen and Pickering said at today's hearing the investigation was neutral.

"I had no sense anywhere that there was any conflict of interest," Pickering said. "I saw a staff that worked many extra hours, that looked very carefully at all the issues, that did extraordinary research for us, was highly responsible to us."

Another point of contention: Clinton and Cheryl Mills, the former secretary's counselor and chief of staff, were shown a draft of the report before it was released.

"Don't convey it as independent," Rep. Jim Jordan, R-Ohio, said. "If Cheryl Mills picked you, you gave her a heads-up within days of starting, and you let them look at the report and edit the report at the end, that's all fine if that's the way the statute reads. But don't try to tell us that it's independent."