BBC defence correspondent Andrew Gilligan's report about claims that Downing Street "sexed up" the government's Iraq dossier sparked the weapons row.
Andrew Gilligan broke his story in an early morning broadcast
Mr Gilligan's notes of his meeting with government scientist Dr David Kelly were put in the spotlight at the Hutton inquiry.
And he acknowledged "slips of the tongue" in some broadcasts about what his anonymous source had said.
It was claimed too that Mr Gilligan failed to give the Ministry of Defence details of his story about the dossier before it was broadcast.
There were three key areas where Mr Gilligan's role came under question as the inquiry unfolded:
NOTES OF DR KELLY'S COMMENTS
Mr Gilligan's meeting with his anonymous source, Dr Kelly, at the Charing Cross Hotel has become infamous.
His barrister said meeting such sources added to healthy political debate.
The Today programme correspondent said he did not take notes from the start of the meeting but asked the weapons expert if he could when he started talking about interesting topics.
He presented a print-out of notes he had made at the time on his handheld computer.
Those notes included the claim that the dossier had been "transformed" the week before its publication, something Mr Gilligan said Dr Kelly had pinned on Downing Street media chief Alastair Campbell.
The scientist's friend, Olivia Bosch, claimed Dr Kelly had told her he had been "taken aback" when Mr Gilligan played a "name game" with him to elicit Mr Campbell's name.
Kelly family lawyer Jeremy Gompertz also suggested it was Mr Gilligan who first mentioned the spin doctor's name.
And government QC Jonathan Sumption said Dr Kelly may well have said more to the BBC reporter than he admitted to his MoD bosses, but it was still less than he was reported as saying.
Mr Gilligan instead insisted he had agreed with the scientist which quotations he could use in his broadcast.
But concerns were raised about apparent "anomalies" in his electronic notes of the conversation.
One forensic computer expert was worried about why Mr Campbell's name did not appear in the first memo on the reporter's handheld computer.
"Somebody was looking at creating memos and seeing if dates and times could be changed," he said.
Mr Gilligan denied conducting any such experiments. He said the memo which first mentioned Mr Campbell was a file created at the end of the conversation when he was agreeing which quotations he could use.
The Hutton inquiry saw Mr Gilligan's broadcasts put under the spotlight word by word.
In particular, he was put under pressure for his early morning two-way - when he was interviewed by a presenter.
In that first broadcast, he said: "What we've been told by one of the senior officials in charge of drawing up the dossier was that actually the government probably knew the 45 minute figure was wrong, even before it decided to put it in."
This led to him being charged with accusing the government of lying and was cited as a key reason why Downing Street took the affair so seriously.
Mr Gilligan admitted his wording had not been perfect in the first broadcasts but in 19 later reports he never suggested the government had known the 45-minutes claim was wrong.
"It was not intentional, a kind of slip of the tongue. It is something that does happen in live broadcasts," he said.
The inquiry saw an e-mail from Today programme editor Kevin Marsh calling Mr Gilligan's reports a "good piece of investigative journalism marred by flawed reporting".
"Our biggest millstone is a loose use of language and lack of judgement in some of his phraseology," said Mr Marsh.
The way Mr Gilligan described his anonymous source, Dr Kelly, as "one of the senior officials in charge of drawing up the dossier" was also challenged by the government's barrister.
The reporter maintained he had agreed that description with Dr Kelly.
But he admitted making a mistake in talking of "my intelligence source" in one broadcast.
He had been scrupulous, however, not to say he was a member of the intelligence services, he argued.
Challenged on why he had not corrected a BBC press release referring to an "intelligence source", he said: "There was not very much I could do about it.
"The BBC - and other media organisations - don't work in a way where the reporters can tell the governors what to say."
Mr Gilligan also apologised for the e-mails he sent to MPs looking into his BBC story.
He had been "quite wrong" to suggest Dr Kelly was the source for BBC Newsnight's weapons reports, especially as he was not sure at the time who the source was.
In his defence, he said he had been under "enormous pressure" at the time.
Downing Street media chief Alastair Campbell said it was extraordinary that the dossier allegations were broadcast without being first put to the government.
But Mr Gilligan said he had told Ministry of Defence chief press officer Kate Wilson the "gist" of the claims the evening before his report.
That was so she could brief Armed Forces Minister Adam Ingram to respond when he was interviewed about cluster bombs.
Mr Gilligan said he had not spoken in any depth about the cluster bombs story, which was being handled by another reporter.
But Ms Wilson said the issue dominated their conversation.
She added: "At the end of the conversation I asked him whether there was anything else running on the programme and he said he had something he was working on WMD and the dodgy dossier.
"He said it was not a matter for the MoD so I did not pursue it."