It was certainly pretty disastrous for Tony Blair. His ill-judged intervention in the contest, suggesting that any departure from New Labour would consign the party to the wilderness, appears to have spectacularly backfired.
Offered the chance to choose a Blairite continuity candidate in David Miliband, the comrades opted instead for someone who has spent most of his career as an adviser to Gordon Brown.
Mr Blair's autobiography may have topped the best-seller charts. But it has lost him any lingering influence he may have had over his old party.
But if this week's conference in Manchester was a disaster for the Blairites, how was it for the party as a whole?
Well, on this point, I'm afraid I find myself in rare agreement with the former Prime Minister.
Had David won, Labour would have been right back in the game. Unlike his younger brother, he is a man who is ready to be Prime Minister now, and his election would instantly have struck fear into the coalition.
Instead - and not for the first time in its history - the party has opted to eschew the easy route back to power in favour of the long, hard road.
To my mind, there are three principal reasons why Ed's victory may ultimately come to be seen as a bad day's work for the party.
The first is nothing to do with the qualities of Ed or David, but with the flawed system that enabled Ed to come out on top despite winning fewer votes from both party members and MPs.
Much has already been written about the dangers of Ed being seen to be in the "pockets" of the union bosses, and like many Labour leaders before him, he will have to work hard to tackle that perception.
To me, the bigger problem is not that the unions got their man, but that the party members didn't, creating an issue of legitimacy that Ed will struggle to address.
Secondly, there is Ed himself. He was right in his speech on Tuesday to try to draw a line under some of the issues which have caused Labour to suffer such a catastrophic loss of trust, and the 'Red Ed' jibes will soon be shown to be ludicrous.
But for all his personal ruthlessness in fighting his elder brother for the party leadership – and in despatching Nick Brown from the job of Chief Whip - he still comes across as rather earnest and well-meaning.
For me, though, the biggest danger for Ed is that, in displaying such ruthlessness in pursuit of the top job, he may have sown the seeds of his own downfall.
It is not just that in order to win the leadership he had to humiliate his elder brother and force him out of frontline politics, but that he also had to trash the entire New Labour brand.
Yes, there were things New Labour got wrong. It did become "fixed in its own certainties" as Ed said on Tuesday. The Blairites became, like Tony Crosland, revisionists who stopped revising.
And as the North-East knows only too well, it clearly failed to balance the interests of its traditional supporters against those of 'aspirational' voters.
But the essential lesson of New Labour – that to win, the party needs to reach out beyond its ideological comfort zone - is one Ed Miliband ignores at his peril.
And I am not alone in wondering whether in declaring New Labour 'dead,' he is not also in danger of writing his own political obituary.
