Nothing in his quiver of answers for members of Congress during long-anticipated testimony Wednesday contained much information.

When he wrapped up the Russia investigation with a public statement back in May, the former FBI Director and special counsel said that written document was his testimony.

Now, called before Congress as a private citizen, his actual spoken testimony consisted largely of throwing back to it and doing everything he possibly could to not get caught up in the political fight. Mueller didn't do much to help Americans who haven't bothered to read the document , which lays out scores of interactions between the Trump campaign and Russians, and dissects ten possible instances of obstruction of justice by Trump, and documents 77 lies and falsehoods but didn't recommend any specific conspiracy or obstruction charges.

Where previous special counsels like Whitewater's Kenneth Starr recommended impeachment, Mueller remained frustratingly opaque in a way that on Wednesday came off as obtuse at times.

Mueller refused to explain what's in the space between "not exonerated" and not indicted, although he did make clear the option of indicting Trump was never open to him, according to Department of Justice guidelines. He later clarified that the question that made this point, and which he agreed to, wasn't exactly the right way to put it.

It was on one hand refreshing to see a congressional witness answer simply and maddening because both Democrats and Republicans actually wanted answers from him.

What was left for Democrats was to read incriminating sections from the obstruction of justice portions of the redacted report and for Mueller to verifying them.

And for Republicans, it was an opportunity to poke holes in the report's reasoning and try to tie Mueller in knots, which they did to some effect as he shuffled through the redacted version of the report in a three-ring binder containing the report and trying to follow along.

One key knot was tied at the outset when Mueller said, "No," collusion and obstruction of justice weren't the same thing, during questioning by Rep. Doug Collins, a Georgia Republican.

The exchange is emblematic of the hearing.

COLLINS: Although your reports states, "collusion is not some specific offense," -- and you said that this morning -- "or a term of art in federal criminal laws, conspiracy is." In the colloquial context, are collusion and conspiracy essentially synonymous terms?

MUELLER: You're going to have to repeat that for me.

COLLINS: Collusion is not a specific offense or a term of art in the federal criminal law. Conspiracy is.

MUELLER: Yes.

COLLINS: In the colloquial context, known public context, collusion -- collusion and conspiracy are essentially synonymous terms, correct?

MUELLER: No.

COLLINS: If no, on page 180 of Volume 1 of your report, you wrote, "As defined in legal dictionaries, collusion is largely synonymous with conspiracy as that crime is set forth in the general federal conspiracy statute, 18 USC 371."

MUELLER: Yes (ph).

COLLINS: You said at your May 29th press conference and here today you choose your words carefully. Are you sitting here today testifying something different than what your report states?

MUELLER: Well, what I'm asking is if you can give me the citation, I can look at the citation and evaluate whether it is actually...

COLLINS: OK. Let -- let me just -- let me clarify.

You stated that you would stay within the report. I just stated your report back to you, and you said that collusion -- collusion and conspiracy were not synonymous terms. That was your answer, was no.

MUELLER: That's correct.

It continues from there.

Either unflappable or hard of hearing, Mueller did not betray emotion or fight back even when Republicans attacked his credibility and judgment.

JUST WATCHED Lawmaker goes on angry tirade during Mueller questioning Replay More Videos ... MUST WATCH Lawmaker goes on angry tirade during Mueller questioning 00:12

For Democrats, their attempts to draw Mueller out of his shell were futile.

"Director Mueller, the most important question I have for you today is why Director Mueller, why did the President of the United States want you fired?" Rep. Ted Deutch, a Pennsylvania Democrat, asked,.

"I can't answer that question," Muller answered.

The clipped deadpan had an effect and raised questions about Mueller's ability to go further.

There was a moment much later, before the House Intelligence Committee, when Mueller was asked by Democrat Val Demmings of Florida if he thought the President was credible.

"I can't answer that question," Mueller said.

She followed up asking if, after refusing to testify and instead answering questions from Mueller's team in writing, the President's answers were inadequate, incomplete and not always truthful.

"I would say generally," Mueller said.

That's not a good answer for the White House, but it isn't exactly breaking news. The question is whether further movement toward impeachment hearings requires theatrics from Mueller to push Democrats toward action. If so, there will be none.

"I think the question of how he's, this very limited short sentences, yes or no, is that a strategy or is that something he's just not capable of doing?" said CNN legal analyst Jeffrey Toobin.

Preet Bharara, the US Attorney fired by Trump early in his administration, suggested people deserved more from Mueller.

"I would like to hear a stronger answer as to why it was appropriate to continue the investigation because the implication of it is as a lot of people are speculating, you do the investigation, you can continue to investigate and there's a body called Congress that also has the -- you know, an interest in this and future prosecutions once he leaves office. So it was not all for naught."

Rep. Adam Schiff, the chairman of the House Intelligence Committee, said he would take up the written report to fill in the blanks of what Mueller intentionally would not say.

Multiple former FBI officials either fired or openly attacked by Trump have testified about this investigation in a very different way than Mueller.

Two years ago, James Comey, who was appointed FBI Director after Mueller left the post, was a smooth-talking showman who sparred back and forth with lawmakers and used the platform to question Trump's fitness to be president

Last year, Peter Strzok, whose text messages with Lisa Page fueled conspiracy theories that inquiries into collusion were stacked against Trump, testified in anger

Mueller, who has been personally attacked repeatedly by Trump stayed as neutral as humanly possible, which gives him the benefit of appearing, somehow, still impartial. But also robotic. His testimony isn't likely to change any minds about Trump's attempts to get in the way of the Russia investigation in large part because Mueller isn't, or can't, translate his report for the Capitol Hill circus.