Chris Patten, the chairman of the BBC Trust, today told Andrew Marr that the BBC was facing its worst crisis since the Hutton Inquiry.
He said that "awful" journalism had "disgraced" Newsnight, and therefore he understood why the director-general, George Entwistle, had resigned.
Marr asked him whether Entwistle's "car-crash interview" with John Humphreys on Radio 4's Today programme had contributed to his decision to leave. "You don't go on an interview with John Humphreys and expect the bowling to be slow full tosses," Patten replied.
"We're a news organisation and our credibility depends on telling the truth," he added.
Marr asked whether Entwistle's "lack of curiosity" about the incorrect Newsnight story was the problem. Patten agreed partially, adding "from the beginning… he was implicated in the crisis. He was director of vision when that first Newsnight programme went out".
However, he said, Entwistle was "cerebral, decent, honest, brave".
Asked about his own position, Patten said that it was "bound to be under question by Rupert Murdoch's newspapers, let's be clear about that".
But he later added that opponents of the BBC "are fairly cagey about the way they talk about it" because of the corporation's wide public support. "It is one of the things which defines Britishness."
As for the suggestion that Newsnight was "toast" - as presenter Eddie Mair suggested on Friday's programme - Patten said: "That's a rather quick judgment … at the heart of our journalism is good investigative, uncompromising journalism, and Newsnight been part of that tradition. We want to hold on to that. We want to make sure that Newsnight and other programmes are properly managed.
"It's obviously been compromised by the fact that senior executives were recused from involvement . . . [but] decisions about the programme went up through every damned layer [of management]".
After Andrew Marr complained about the existence of an out-of-touch "senior management group" at the corporation, Patten said that he had always joked there were "more senior leaders at the BBC than in the Chinese communist party" but that it had worked to change itself.
The BBC Trust chairman promised to appoint a replacement for Entwistle within weeks, and not to let the corporation become too risk-averse.