If Ed Miliband allowed himself to gloat over David Cameron being ambushed at the EU summit, and the Tories' battle with UKIP becoming even harder, he would have been foolish and even more out of touch than his critics claim he is.
Margaret Thatcher famously said that "in politics, the unexpected always happens". And the Labour leader probably wasn't expecting his party to be plunged into a civil war by the resignation of its leader in Scotland – just 24 hours after the Prime Minister was exploding in fury in Brussels.
But Johann Lamont's resignation, after what her critics claimed was a lacklustre performance in the Scottish referendum campaign, wasn't unexpected. Mr Miliband and many Scottish Labour MPs at Westminster say they knew earlier this week that it was coming.
What was unexpected was the ferocity of her onslaught on Mr Miliband and the Labour leadership in her valedictory interview in Scotland's Daily Record, triggering tartan turmoil in the party and revealing splits, rows and bitterness between Westminster and Holyrood.
She accused the Labour leadership in Westminster of treating the Scottish party as a "branch office" and branded some Westminster Labour MPs "dinosaurs… who think nothing has changed".
She complains that the party's Scottish general-secretary was ousted without her being consulted, making her position "untenable".
And, I'm told, she also wanted Eric Joyce kicked out of Parliament after his Westminster bar room brawl, rather than be allowed to remain as an MP sitting as an independent.
Many will agree that she's right about Westminster "dinosaurs". Many Scottish Labour MPs are still guilty of shocking complacency, despite Alex Salmond winning an overall majority in the Scottish Parliament in the election of 2011, just before Johann Lamont became leader.
Those same Scottish Labour MPs, although no doubt mightily relieved by the No vote in the referendum, still don't seem to grasp the real threat that the SNP poses to Labour in many of its heartlands in the 2015 General Election, based on strong Yes votes in some of those strongholds in the referendum.
Labour currently holds 41 of the 59 Westminster seats in Scotland. And, leaving aside the row over "English votes for English laws", it needs to hold on to those – or even make a few gains – if Ed Miliband is to have any chance of becoming Prime Minister.
Yet it's estimated that one in three Labour supporters voted Yes in the referendum. And if that haemorrhaging of support was repeated in the General Election, Labour's 41 seats would be down to about 30. That could make the difference between Labour being in Government and staying in the Opposition.
In other words, however well Labour does against the Conservatives and Liberal Democrats in English and Welsh marginals, Labour losses to the SNP could rob Mr Miliband of an overall majority, or of leading the largest party in the Commons.
So the Labour disarray, rancour and infighting unleashed by the departing Johann Lamont won't just send shock waves throughout Scotland. It threatens to change the landscape in the whole of the UK.
If there was any gloating by Ed Miliband at David Cameron's Euro-nightmare, it will now have been brought to an abrupt end.
And just who will succeed Johann Lamont? Anas Sarwar? Jim Murphy? Gordon Brown? The job is beginning to look like a poisoned chalice.
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Gallery: Who Will Be The Next Scottish Labour Leader?
Some of the politicians tipped to succeed Johann Lumant: Anas Sarwar is the MP for Glasgow Central, and will assume the role of acting leader of the Scottish Labour Party until a ballot takes place
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Kezia Dugdale became an MSP for the Lothian Region in 2011, and also writes a column for the Daily Record, the same newspaper used by Johann Lumont to criticise the Labour Party
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Gordon Brown, the former Prime Minister, has also been tipped for the role. He returned to front-line politics by encouraging the public to vote No in the independence referendum
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Jim Murphy had insisted he was not going to begin a leadership challenge against Johann Lumont, but all that could now change now she has resigned
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Douglas Alexander, the MP for Paisley and Renfrewshire South, already has a meaty role in Westminster as shadow foreign secretary
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Jenny Marra is another MSP who entered Holyrood in 2011. She is deemed to have an outside chance of becoming the Scottish Labour leader
The one person who is gloating this weekend, despite falling short of victory in last month's referendum, is the cocky Alex Salmond, who couldn't resist pointing out that Scottish Labour is now going to have its fifth leader since he become Scotland's First Minister in 2007.