Attorney General William Barr previously said he believed it was his responsibility to make a determination in whether President Trump obstructed justice following the Mueller report — yet he repeatedly blamed the special counsel during congressional testimony on Wednesday for not doing so.

“The Special Counsel’s decision to describe the facts of his obstruction investigation without reaching any legal conclusions leaves it to the Attorney General to determine whether the conduct described in the report constitutes a crime,” Barr previously stated in a summary of the report he released to Congress. While testifying in front of the Senate Judiciary Committee, however, Barr questioned why Mueller hadn’t offered a clearer decision himself.

“I think the deputy attorney general and I thought it was [Mueller’s responsibility to make a charging recommendation],” he said, noting that he was “surprised” the special counsel did not. “Not just charging, but to determine whether or not conduct was criminal.”

Barr fielded criticism in the wake of a letter that surfaced late Tuesday indicating that Mueller wasn’t exactly satisfied with a four-page summary of the report he offered. During Wednesday’s hearing, Barr took the opportunity to go on the offense.

In addition to questioning Mueller’s reasoning for not charging Trump with obstruction, which included the citation of Justice Department policy that restricts the indictment of a sitting president, he suggested the special counsel’s actions raised the question of why he even opened up this aspect of the investigation in the first place.

“I think that if he felt that he shouldn’t go down the path of making a traditional prosecutive decision, he shouldn’t have investigated it. That was the time to pull up,” Barr said.

As the Washington Post notes, Mueller opted to investigate 10 episodes of possible obstruction of justice because he wanted to “preserve the evidence when memories were fresh and documentary materials were available.”

The instances Mueller investigated included Trump’s firing of FBI Director James Comey, his efforts to curtail the Russia investigation, and his direction to White House counsel Don McGahn to remove Mueller. In their conclusions, Mueller’s team noted that they did not have sufficient evidence to exonerate Trump, and were, in fact, so uncertain of his lack of culpability that they refrained from explicitly stating it.

“If we had confidence after a thorough investigation of the facts that the President clearly did not commit obstruction of justice, we would so state,” the report reads.

Because Mueller declined to bring charges himself, Barr determined that he should make a final decision on obstruction and concluded that there wasn’t enough evidence to indicate the president had engaged in it, alongside Deputy Attorney General Rod Rosenstein. His decision to effectively clear the president and frame the report in a light that was incredibly favorable to him wasn’t necessarily the obvious next step, however.

As Harvard Law School professor Noah Feldman writes for Bloomberg, it’s possible that Mueller’s unwillingness to definitively charge or exonerate Trump meant that Barr wouldn’t be able to make this decision either, since they were operating off the same evidence. Additionally, as Vox’s Ella Nilsen writes, the report offered a seeming road map for Congress to continue investigations on obstruction of justice.

Ideally, as Democratic lawmakers have said, there’s at least one solution that could help provide more clarity about this issue: Mueller would be able to address some of these questions by testifying in front of Congress himself.

But as the Daily Beast reported on Wednesday, House Democrats say the Justice Department could be standing in the way.