Joan Smith: Ross is out, but it's the BBC that is on the back foot

The single most important thing that happened last week, obviously, was the shock announcement that Jonathan Ross is leaving the BBC. His not-so-imminent departure – we have until the summer to prepare ourselves – was reported exhaustively, getting top billing on Radio 4's PM programme.

The editors considered it such a sensational development that they put together a full package of analysis and interviews just to make sure listeners had grasped the breathtaking implications; the only thing missing was a live link to Downing Street where, sadly, Gordon Brown was too preoccupied to offer the reassurance the nation sorely needed.

At one level, this kind of saturation coverage of a trivial event is a symptom of poor editorial judgement: Ross is famous, but he isn't important. After his cheap jibes in 2008 about Andrew Sachs's granddaughter, he isn't even that popular; he is a poster boy for a group of celebrities notable for self-promotion and their ability to persuade the BBC to pay them absurd quantities of money.

David Cameron publicly criticised the corporation over the Sachs affair, while the shadow Culture spokesman, Jeremy Hunt, has put the BBC on notice about its top-heavy pay structure: "We must see a full breakdown of what the BBC pays its celebrity talent. It is licence fee-payers' money and full transparency is a must."

We can assume such pronouncements aren't music to the ears of Mark Thompson, the BBC director-general, and that senior managers are expecting cuts if the Conservatives form the next government. And I wonder if this background goes some way towards explaining the most mysterious aspect of last week's events: was BBC management reticent about the precise circumstances of Ross's departure because they were reluctant to hand the Tories a big scalp? The corporation seems to have been caught off-guard and for several hours allowed the presenter to make all the running; Ross cheerfully served tea to reporters outside his home, sounding like a man who had regretfully decided to move on.

Yet it was reported just before Christmas that he was so keen to continue presenting for the BBC that he had offered to take a 50 per cent pay cut. I never quite trust the figures bandied about by anonymous "sources", but it didn't sound as though Ross was confident that he had a future at the corporation. Now he says he isn't leaving because of money, and I believe him.

What I haven't seen is anything to suggest that the BBC wanted him to stay when his present contract expired. Ross confirmed in his own statement that no negotiations had taken place. Many people think he should have been fired in 2008, and public attitudes to pay have shifted dramatically in the past year; even if Ross's three-year contract didn't amount to the widely reported £18m, it was negotiated when public finances were in much better shape.

Thompson squirmed when Baroness James confronted him on the Today programme about levels of pay. And the BBC's creative director, Alan Yentob, startled viewers on Newsnight last week when he suddenly said that legislation (which no one had mentioned) would not be necessary to curb high BBC salaries.

None of this suggests that the BBC's senior managers are in confident mood. If they were, they might have fought to keep Ross; equally, they might have said upfront that they had decided against offering him a new contract. That's the real story: not the departure of a controversial presenter, but further evidence of defensiveness and paralysis at the BBC.