On Monday night I heard one of David Miliband's aides remark to him: "you will be guarded, won't you?", as he prepared to enter Labour's annual Diversity Nite. With an audible sigh, he replied: "oh, for God's sake". But her words proved prescient.
During the leader's speech, ITV news cameras picked up the elder Miliband, with a look of pure murder on his face, leaning towards Harriet Harman as she happily applauded his brother's condemnation of the Iraq war. According to the station's lipreaders, he said: "Why are you clapping? You voted for it." To which Harman is said to have replied: "I'm clapping because he's leader and, as you know, I'm supporting him."
The remark reveals more than Miliband's dislike of those who claim to be wise after the event. It betrays his intense frustration at the way Ed's opposition to the Iraq war (thanks to my colleague Mehdi Hasan, for instance, we now know that he lobbied Gordon Brown to oppose the war) helped give him the edge in the leadership contest.
Just as Cherie Blair's "liar" attack famously overshadowed all coverage of Brown's 2006 speech, I expect Miliband's words will do the same today.
David has now left the conference and headed back to London. And, whatever his response to tonight's news, it's looking even more unlikely that he'll serve in Ed's shadow cabinet.