For me, the Telegraph 'sting' was a legitimate journalistic exercise to attempt to address an important political issue: what are senior LibDems really saying about the Coalition government in the party or in their constituencies? The view is widely expressed that Cable was daft to get caught out. But it would also be absolutely fatal to the LibDems if they were not having these type of conversations inside local party meetings - though many are taking the view that politicians should not, ideally, be honest or candid with constituents on a first meeting.
For all of the post-event wisdom of the commentariat, on the basis of the Telegraph's initial transcript this morning, Cable was being charged mainly with candour. He was not impolite even to Tory colleagues, and offered a broadly accurate reading of the political situation.
Cable is a decent liberal politician (and indeed still something of a social democrat to boot) in a rather difficult position by the central thrust of this Cameron-Clegg-Osborne Coalition. Cable's description of the internal politics of Coalition will chime rather better with many LibDem members and activists - and still more with their anxious voters - than the rather bizarre idea sometimes given voice by the Clegg-Laws wing of the party leadership that the LibDems suddenly discovered during the May Coalition talks that the Tories were soulmates and intellectual allies after all.
Indeed, what should worry LibDems most is not Cable's (quite probably accurate) description of his nuclear option, but the observation that he does not have any conventional weapons: ie, that he lacks influence on decisions within government without the (difficult to use often) threat of exit.
Many members of the government are habitually much ruder about colleagues in private - albeit usually protected by "lobby terms" in offering these indiscretions to grateful journalists: take Nick Clegg's comments on a plane deriding frontbench colleagues who has now given ministerial posts, Chris Huhne's "Calamity Clegg" briefing paper, or 10 Downing Street's barely disguised animosity towards Liam Fox, to say nothing of the personal animosities of a previous government.
Cable's comments about Rupert Murdoch are in a different category. This was a bad error - and the government's decision to remove Cable's role in media regulation is an appropriate and correct response.
After his comments were made public, Cable could not claim to be in a position to judge the News International/BSkyB issue impartially. One might, however, be forgiven a sceptical thought as to how far Culture Secretary Jeremy Hunt may find Solomon-like wisdom and detachment on offer to him in inheriting these responsibilities.
How they must be laughing at Cable's error in News International - an organisation which declared war on Nick Clegg, Vince Cable and the LibDems (using CCHQ ammunition) during the election campaign well before Mr Cable was in a position to take any view about them, no doubt without any hope or expectation of such favours being remembered should the government ever have the statutory responsibility to look impartially at the company's business.
So they did not welcome Cable's appointment - at a time when News International has been on the backfoot, because nobody in journalism or politics sincerely believes its account of the law-breaking culture is credible (as Andrew Neil has impolitely pointed out) - and now they are rid of him.
Cable's failing was in hyperbolic language, not least in overstating the impact of the Sky decision on "the Murdoch Empire".
It is largely forgotten, with New Labour invariably painted as Murdoch's lackeys, the government did refer BSkyB's proposed takeover of Manchester United to the Competition Commission in 1998, which blocked it. (As Stephen Byers undoubtedly gave his enemies some ammunition in the following years, I have no substantive evidence from which to suppose that NI papers were not entirely fair and impartial in their later tough treatment of him, even if Rupert Murdoch is widely thought to have the ability to remember a slight). James Purnell later cited that decision at a Fabian conference as evidence that Labour's approach to News International had been that of "fairness, not favours", language which might also well have suited Cable's purposes admirably).
Would the government have acted quite as quickly were a Business Secretary making hostile private comments about Cable's former employers Shell, or BP's troubles in Mexico, or how tax avoidance issues affect the reputation of Sir Phillp Green, or other large firms? Perhaps they would have been just as firm as when Mr Murdoch was slighted.
A coalition of the willing?
Or might the lesson be that any politicians who even thinks of crossing Rupert Murdoch can expect to come to a sticky end?
If Vince Cable wanted to play a longer game on that front, he could find some unusual allies for a different type of political coalition, as long as he could resist making the tactical mistake of shooting too early.
Chris Mullin recounts this interesting encounter with John Major, which this blog has noted before, in the first edition of his justly acclaimed diaries
Tuesday 5 December
A quiet chat with John Major who confirmed that he had contemplated banning foreign ownership of British media. He said he had been provoked by the continual attacks on him in the Murdoch press and in the Telegraph, which is owned by Conrad Black, a Canadian. I asked if he had commissioned any work on the subject and he said he had, but it was buried with the papers of the last government. He added 'I'm not interested in any blow that isn't fatal'. Me neither.
(page 143), A View From the Foothills, by Chris Mullin (Profile)
Mullin later finds that Tony Blair sympathises, in an idle reverie at least, though you can sense that his heart is not in it.
The Man laments the wickedness of the media and interference by Murdoch. I mention that John Major once thought seriously about breaking up the empires - one daily, one Sunday, everything else on the market - but dropped the idea because those queuing to buy are at least as unsavoury as existing owners.
'Oh I don't know', he says, 'There are Germans and other Europeans who would be much better'. I press the point: 'You would have to strike with deadly force, a week after we win a third term'. He is about to reply, but stops himself. He did remark firmly that the owners of the Mail would never be allowed to get their hands on the Telegraph.
Perhaps Blair's apparent reference to "interference by Murdoch" is a typo or some kind of misunderstanding.
But I am sure Mr David Cameron will want Mr Hunt and other ministers to think of nothing other than fairness and impartiality, those core features of our media environment.