In a surprise press conference at the Department of Justice, special counsel Robert Mueller announced that his office’s investigation into 2016 election interference is complete, summarized its findings about Russia’s attacks on the Hillary Clinton campaign, emphasized that he had not cleared Donald Trump of committing obstruction of justice, and said he would prefer not to testify to Congress.

On the subject of obstruction, Mueller reiterated the previously issued special counsel report’s text by noting that “if we had confidence that the president clearly did not commit a crime, we would have said so” and that the special counsel did not “make a determination as to whether the president did commit a crime.” He then referred to a preexisting DOJ Office of Legal Counsel document which holds that, under existing law, a sitting president cannot be criminally indicted by the federal government. (The president, of course, can be impeached.) Said Mueller: “The introduction to the volume two of our report explains that decision. It explains that under long-standing department policy a president cannot be charged with a federal crime while he is in office. That is unconstitutional. Even if the charge is kept under seal and hidden from public view, that too is prohibited. The special counsel’s office is part of the Department of Justice and by regulation it was bound by that department policy. Charging the president with a crime was, therefore, not an option we could consider.”

Mueller’s account adds some clarity, if you will, to earlier comments made by Attorney General William Barr, who said the following at a previous press conference:

When we met with [Mueller] … we specifically asked him about the OLC opinion and whether or not he was taking a position that he would have found a crime but for the existence of the OLC opinion. And he made it very clear several times that that was not his position. He was not saying that but for the OLC opinion, he would have found a crime.

What appears to be happening here is parsing, or spin, in which Barr is using Mueller’s statement that the OLC opinion prevented him from considering whether to accuse Trump of a crime to imply that Mueller wouldn’t have charged Trump with a crime even if the OLC opinion didn’t exist. But that does not appear to be Mueller’s position. (According to CNN, Barr did not ask Mueller to make the statement but was briefed on its contents.)

After discussing the report, Mueller made clear that he would prefer not to testify about its contents before Congress:

I hope and expect this to be the only time that I will speak to you in this manner. I am making that decision myself. No one has told me whether I can or should testify or speak further about this matter. There has been discussion about an appearance before Congress. Any testimony from this office would not go beyond our report. It contains our findings and analysis and the reasons for the decisions we made. We chose those words carefully and the work speaks for itself. And the report is my testimony. I would not provide information beyond that which is already public in any appearance before Congress. In addition, access to our underlying work product is being decided in a process that does not involve our office. So beyond what I have said here today, and what is contained in our written work, I do not believe it is appropriate for me to speak further about the investigation or to comment on the actions of the Justice Department or Congress.

Mueller concluded by asserting that his office’s allegation that Russia made “multiple, systematic efforts to interfere in our election” is one that “deserves the attention of every American.” He then declined to answer a reporter’s shouted question about whether he would appear before Congress if subpoenaed, left the lectern, and walked out of the room. And that’s that.