The decision to drop the BBC Newsnight investigation into the Jimmy Savile sexual abuse claim was "flawed", according to a review.
A failure to follow editorial guidelines led to Newsnight's infamous report that saw Lord McAlpine later falsely exposed as a paedophile.
A damning report into the BBC's Jimmy Savile investigation has revealed George Entwistle was previously warned about his "darker side".
Last night's closing credits of Newsnight acknowledged the gaffe by its editor Ian Katz after he accidentally tweeted that Labour's shadow Treasury minister Rachel Reeves was "boring" and "snoring."
The former Guardian deputy editor meant to send his remarks in a private message but instead posted it to his 27,000 followers.
Mr Katz issued a written apology to Labour and Ms Reeves for his comments.
Former Newsnight editor Peter Rippon has been appointed to a new role at the BBC -overseeing the online BBC News archive.
Rippon was at the helm when Newsnight dropped an investigation into disgraced TV presenter Jimmy Savile. He 'stepped aside' in October last year.
The BBC reports the former editor will help to build a public record of the corporation's television and radio journalism over 80 years. He will take up the post - in London - from February 25.
Speaking to BBC2's Newsnight, the BBC's acting Director General Tim Davie said it had been a "bad and sorry saga", but defended the lack of sackings.
My job is not to just dismiss people, my job is to make a fair and balanced assessment of the facts. We have lost a Director General in this process.
We all need to accept change and the only way to change is to change the culture, and that's not going to be done however many people we call to be dismissed.
It's going to be done by people like me leading the organisation and changing the culture. I want a change of culture, that is what I am all about.
BBC lawyers investigated whether money could be reclaimed from the departing director-general George Entwistle, BBC Trust chairman Lord Patten has said.
Mr Entwistle received £450,000 despite resigning in the wake of a Newsnight report that led to former Tory treasurer Lord McAlpine being wrongly accused of child abuse.
But Lord Patten said lawyers advised that it was not possible to reclaim the money.
Interviewed after the Pollard Report revealed worrying failures in communication at the top of the BBC chain of command, Lord Patten also defended the disciplinary action taken against staff.
ITV News' UK Editor Lucy Manning began by asking him why no one had been sacked:
Following the publication of the Pollard Report, which said Newsnight editor Peter Rippon's decision to drop the programme's Jimmy Savile investigation was flawed, he said:
Of course, like everyone at the BBC connected with this case, I will learn lessons from what has happened, as I move on with my career.
The BBC itself has an overriding responsibility to foster and support good journalism, and to respond proportionately when that journalism is challenged.
Nick Pollard has raised questions about whether the BBC has been able to do this, and I agree with him that change is necessary.
Two of the reporters who worked on the original investigation in to Jimmy Savile for Newsnight have spoken outside of the BBC.
Both Liz Mackean and Meirion Jones issued very strong statements criticising the BBC. Ms Mackean said the BBC breached duty to women who said Savile a paedophile.
Mr Jones said that last Christmas the BBC knew that Savile was a paedophile yet decided to run tribute programmes.
He added: "I hope the BBC takes measures to make sure nothing like that will ever happen again".
BBC Trust chairman Lord Patten also said in an interview that it was not true to say there haven't been sackings...(Except it's been a resignation, retirement, other jobs shuffled).
Lord Patten tells me the BBC Trust looked at whether they could get money back from George Entwistle's payoff but lawyers said it wasn't possible.