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:
The decision to drop the BBC Newsnight investigation into the Jimmy Savile sexual abuse claim was "flawed", according to a review.
A damning report into the BBC's Jimmy Savile investigation has revealed George Entwistle was previously warned about his "darker side".