There’s probably no point in scrutinizing each of Attorney General Bill Barr’s errors of fact and judgment during yesterday’s Senate Judiciary Committee hearing, but there was one area of interest that stood out for me.

Sen. Pat Leahy (D-Vt.) inquired about the attorney general’s public assurances that Donald Trump “fully cooperated” with Special Counsel Robert Mueller’s investigation.

LEAHY: You think it is fully cooperating to instruct a former aide to tell the attorney general to un-recuse himself, shut down the investigation, and declare the president did nothing wrong? BARR: I don’t think, well obviously, since I didn’t find it was obstruction, I felt that the evidence could not support an obstruction. LEAHY: I’m asking is that fully cooperating. I’m not asking if that is obstruction. Is that fully cooperating? BARR: Yeah, he fully cooperated.

It’s an odd argument because it’s so plainly and demonstrably false. For one thing, the Mueller report documents, in striking detail, the many instances in which the president took steps to obstruct the investigation – even meeting the statutory threshold for criminal obstruction of justice.

Not to put too fine a point on this, one can interfere with an investigation or one can cooperate with an investigation, but to do both is an impossibility.

But that’s not the only the problem. We also know that the president refused to sit down with investigators, and when he agreed to answer written questions, Trump’s answers were deemed “inadequate” – and in some cases, “incomplete or imprecise”– by Mueller and his team.

This isn’t “full cooperation.” It’s the opposite.

As part of the same back and forth during yesterday’s hearing, we were treated to this exchange:

LEAHY: The president of course declared many times publicly in tweets and at campaign rallies and all that he would testify. He never did testify, correct? BARR: As far as I know. LEAHY: I think you know whether he testified or not. BARR: As far as I know, he didn’t testify. LEAHY: And Mr. Mueller found the written answers to be inadequate. Is that correct? BARR: I think he wanted additional, but he never sought it. LEAHY: And the president never testified. BARR: Well, he never– he never pushed it.

The attorney general’s assertion that Mueller “never pushed” for Trump’s testimony made it seem as if the special counsel considered this unimportant.

That’s not even close to being accurate. Mueller and his team tried for a year to arrange an interview with the president, and despite Trump’s public claims to the contrary, he and his lawyers ultimately refused.

The Mueller report noted that investigators considered subpoenaing the president to compel his testimony, but they decided against it – not out of disinterest, but because they knew the ensuing court fight would delay the process for many months.

I mention all of this in large part because it was one of Barr’s more brazen falsehoods, which was emblematic of a larger concern: he peddled nonsense, under oath, because he thought it would help make Trump look better.

And by all appearances, for this attorney general, that’s an unnervingly important consideration.