Throughout his testimony before the House Judiciary Committee, Robert Mueller exhibited repeated instances of unfamiliarity with his own investigation.

The former special counsel, 74, appeared extremely confused at times as he faced questions from Democrats and Republicans on Wednesday, often asking members to repeat their questions and failing to recognize names.

"Collusion" and "conspiracy"

In speaking about one of the integral parts of the Russia investigation, Mueller contradicted himself on definitions of “conspiracy,” which his team did look for in their investigative examination of the Trump campaign, and “collusion," which they did not due to its lack of a legal definition.

Rep. Doug Collins, the top Republican on the House Judiciary Committee sought to "put to bed" the confusion the public has about the two terms, which are often used interchangeably.

Collins asked Mueller if in a colloquial context the two terms are synonymous. Mueller said they were not, but the Georgia congressman informed him that Mueller's report said they were interchangeable.

He read from the report. "On Page 180, volume 1 of your report it says 'as defined in legal dictionaries collusion is largely synonymous with conspiracy statute as that is set forth in USC 371.' Now you said you chose your words carefully. Are you contradicting your report right now?" he said.

"Not when I read it," Mueller said.

Collins challenged Mueller, who said to look at the language. "I’m reading your report, sir, it's a yes or no answer. Page 180, Volume 1. This is from your report," the congressman said.

"Correct. I leave it with the report," Mueller replied, appearing to concede to the congressman.

Fusion GPS

Mueller declined to answer questions on why any direct mention of Fusion GPS was omitted from his 448-page report on the Russia investigation.

“I’m not familiar with that,” Mueller said when asked about the indirect mention of the opposition research firm in his report.

Mueller’s report said a New York Times story quoted a spokesman for President Trump’s legal team suggesting that the Trump Tower meeting “might have been setup by individuals working with the firm that produced the Steele reporting,” but does not mention the opposition research firm or its founder Glenn Simpson.

The Democratic National Committee and Hillary Clinton’s campaign hired Fusion GPS and British ex-spy Christopher Steele during the presidential election. Steele compiled an unverified dossier on Trump’s alleged ties to Russia.

Rep. Steve Chabot, a Republican from Ohio, pressed Mueller on why Fusion GPS or Simpson were left out of his report on Russian interference in the 2016 presidential election and whether Trump obstructed justice.

Mueller said multiple times the answers to Chabot’s questions were “outside of my purview” and any matter relating to Fusion GPS or Simpson were “being handled by others at the Department of Justice.”

Trump told Sessions "I’m f---ed"

In one exchange, Mueller failed to recall the source of a quote that appears in his report when Trump found out that Mueller had been appointed special counsel in May 2017. "This is the end of my presidency, I'm f---ed," Trump said.

Rep. Steve Cohen, a Democrat from Tennessee, asked Mueller if Jeff Sessions, Trump's first attorney general who recused himself from the Russia investigation, told him about that chat.

"I’m not certain of the person who originally copied that quote," Mueller said. A footnote in the report shows the quote was attributed to notes from Jody Hunt, who was Sessions' chief of staff.

Lewandowski

Under questioning from Rep. David Cicilline, a Democrat from Rhode Island, Mueller had to be reminded who Corey Lewandowski is. Lewandowski, Trump's one-time presidential campaign manager, was mentioned 129 times in Mueller’s report.