The two companies were highly embarrassed this summer when Fincham announced at a press preview that the royal documentary showed the Queen storming out of a photo shoot in a huff, only for it to transpire that RDF had manipulated the footage and re-ordered sequence of events, resulting in a humiliating admission the next day.
Today, the BBC published the Will Wyatt investigation into what went wrong and who was at fault.
Wyatt concluded the affair involved "misjudgments, poor practice and ineffective systems" but he did not believe anyone consciously set out to defame or misrepresent the Queen nor that there was any possibility the misleading sequence would have appeared in the broadcast version of the programme.
However, the report concluded that Lambert was the one who altered the sequence "in a cavalier way" and RDF showed "no thought to what the re-cut sequence now appeared to show".
Lambert, whose offer to resign three months ago was turned down by RDF, today said it was clear to him several weeks ago it would be in the best interests of RDF for him to resign once the report was published.
The tape Lambert worked on was destined to help RDF market the show, but because of poor communication between RDF and the BBC, the re-ordered sequence was unknowingly used for the BBC press launch event.
Going on to deal with the aftermath of the press launch, Wyatt was critical of the failure to speedily produce an explanation of the misleading footage.
This meant that no statement was issued to the press to stop the next day's Sun splashing the story of the "walk-out" and the world's media picking up on the story.
Wyatt attributed some blame to Fincham and other parties, including the Buckingham Palace press office, criticising them for not being aware of how strongly the storm brewing and for not alerting Mark Thompson, the BBC director-general, to the story.
He said RDF had an opportunity to set the record straight on the Thursday morning, but did not, when all parties agreed on a statement that read: "The BBC would like to apologise to both the Queen and Annie Leibovitz [the photographer] for any upset this may have caused."
It was not until the Thursday evening that RDF admitted to having supplied "in error" an early assembly of the footage to the BBC.
The report highlights Fincham and Lambert's conflicting recollections of a meeting they had on the Thursday afternoon. It reads:
"By chance, the BBC One channel controller had a previously arranged business meeting with RDF at 4pm. He had been told minutes before by email that the BBC knew that the mis-edit was RDF’s and had replied, 'I am about to meet RDF and will tell them this'.
"Recollections of the meeting differ. The channel controller recalls that he put it to RDF that they were in fact responsible for the mis-edit and that the reply from RDF's chief creative officer was something like, 'So it appears'. The meeting then went ahead.
"The chief creative officer of RDF, however, remembers it differently; that it was "not news" to the controller at that meeting that RDF was responsible for the mis-edit. It was simply a confirmation of something already disclosed."
Wyatt concluded that the BBC devolved too much of the relationship with the Palace to RDF and should have asserted its own position and interests more forcefully. He recommends that the BBC should introduce crisis spotting and crisis management into training for editorial, marketing and communications staff.
Commenting on the resignation, Jeremy Hunt, shadow secretary of state for the department of culture, media and sport, said: "Peter Fincham has rightly taken responsibility for this serious abuse of viewers' trust and gross misrepresentation of the Queen. However, we won't see a long-term solution until all broadcasters have agreed to a code of practice on editorial standards. This is about honesty and integrity and not just about new job titles and executives."
The following exchange of letters, this morning, between Fincham, controller of BBC One, and Thompson, director-general of the BBC, was published by the BBC today.