WASHINGTON — Attorney General William Barr and special counsel Robert Mueller have been friends for three decades, and their families have long socialized together.

After the events of recent weeks, culminating in Barr's contentious appearance on Capitol Hill Wednesday, it's fair to wonder whether that remains the case.

If Barr's appearance before the Senate Judiciary Committee has made anything clear, it's that he and Mueller are profoundly at odds about Mueller's role, his findings, and even the extent of Mueller's dissatisfaction with the way Barr has informed the public about the outcome of the investigation.

"Bob Mueller is the equivalent of a U.S. attorney," Barr said. "His work concluded when he sent his report to the attorney general. At that point, it was my baby."

Mueller didn't quite see it that way, at least as evidenced by his letter that leaked to the news media Tuesday night — a letter accusing Barr of failing to fully capture the "context, nature and substance" of Mueller's work when he summarized it in March, setting the public narrative for weeks.

Barr insisted that Mueller told him "he was not suggesting that we had misrepresented his report," even though the Mueller letter seemed to suggest otherwise.

That isn't the only point of contention between the two longtime Washington figures. Barr by implication criticized Mueller's failure to render a judgment on whether the president obstructed justice, highlighting a fundamental disconnect over what each man believed was the job of the special counsel.

"We did not understand exactly why the special counsel was not reaching a decision," Barr said, explaining that he and his deputy, Rod Rosenstein, were surprised when Mueller told them. "And when we pressed him on it, he said that his team was still formulating the explanation. Once we heard that the special counsel was not reaching a conclusion on obstruction, the deputy and I discussed and agreed that the department had to reach a decision."

He added, in an implicit rebuke to Mueller and his team: "We don't conduct criminal investigations just to collect information and put it out to the public. We do so to make a decision."

Barr said it would be "irresponsible and unfair" to "leave it hanging as to whether the department considered there had been criminal conduct."

He later added, "I'm not really sure of his reasoning. … I think if he felt that he should not go down the path of making a traditional prosecutorial decision, then he should not have investigated. That was the time to pull up."

Mueller, of course, has not spoken for himself on this matter, although Congressional Democrats plan to give him a chance by calling him to testify. Peter Carr, spokesman for the Office of Special Counsel, declined to comment Wednesday.

Mueller's report says that the office could not clear the president of obstruction, but that officials decided it would be inappropriate even to render a traditional prosecutorial judgment, because doing so could be unfair to the president.

The report then detailed 10 instances of possible obstruction by the president that many former prosecutors say provided more than enough evidence for an indictment.

"I was a federal prosecutor for a long time," NBC News analyst and former U.S. Attorney Chuck Rosenberg said on "Morning Joe." "I've brought cases in federal court and obtained convictions on just a fraction of the evidence that Mueller details."

But over and over again at Wednesday's hearing, Barr explained why particular examples cited in the report did not amount to obstruction, speaking in a way that might allow an uninformed observer to mistake him for the president's defense attorney.

At one point, Barr explained to Sen. Amy Klobachar, D-Minn., why he thought the president's comment that Paul Manafort is "a brave man for refusing to break" was not an illegal obstruction of justice.

Barr began his answer with the phrase, "I think what the president's lawyers would say … "

Mueller had a different take on the obstruction question.

"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," his report says. "Based on the facts and the applicable legal standards, we are unable to reach that judgment. Accordingly, while this report does not conclude that the President committed a crime, it also does not exonerate him."