Disregarding the political carelessness of her comments, they also breached the agreement because Labour was not warned in advance that Turei was going to posit such a controversial policy. Andrew Little and John Key seized on them.
Little needed to distance himself quickly from the Green policy. The only thing scarier than the prospect of falling house values for a home-owner is a politician with a plan for falling house values - and Labour cannot be associated with that plan.
Home ownership rates have been declining, but at 63 per cent, it is still a significant group whose sense of present and future security is tied up in property.
Labour's plan to address the supply and demand side of Auckland housing, combined with the new Up and Out unitary plan, may indeed result in lower house prices. But the official aim is to "stabilise" prices, to reduce the rate of increase, as is National's.
Key clearly couldn't believe his luck.
Since the MOU was signed, as a symbolic non-aggression pact, he has been looking for ways to link Labour to the more scary elements of the Greens.
The MOU is actually a fairly chaste set of rules for co-operation between the Greens and Labour, which Key will turn into an orgy at any opportunity.
They are married. They are in bed together, he said this week.
All complete tripe but it will be repeated many times between now and the next election, to tar Labour with a Green brush.
You can hear it already: A Green-Labour Government says house values must fall. It is a gift that National will return to no matter what qualification the Greens put around it and no matter how much Labour seeks to distance itself from it.
It is exactly what happened when the Greens decided to flirt with the idea of money printing to bring down the exchange rate and top up the EQC disaster fund. National invoked notions of currency collapses on a par with Zimbabwe, the value of savings being eroded and linked the whole catastrophe to Labour's economic plan. The Greens formally put up the white flag on the policy the following year but that didn't stop the damage being done.
The encouraging difference between then and now is that Labour learned from it.
Little quickly ruled out any association with Turei's comments. By comparison it was almost sanguine over quantitative easing, merely pointing out that a political party shouldn't be telling the Reserve Bank what to do and that it could print money already.
The Greens promote themselves as a party of principle and courage.
Turei was attempting to meet the challenge of former National leader Don Brash who told me three weeks ago that politicians of the left and right were terrified of saying house prices had to fall.
She later described her own comments in terms of political courage.
Somebody has to be "brave enough" to talk about cutting house prices so a rational conversation about how to do it could begin.
So she was primed to make her comments to RNZ's Guyon Espiner. She was not ambushed or taken out of context. It was a premeditated act of "courage". Let's see how "brave enough" she and co-leader James Shaw are in the coming weeks to stand by their policy of falling house prices. The incident throws up a more strategic question though, and that is why are the Greens trampling all over the housing patch that Labour's Phil Twyford has outstandingly marked out over the past three years.
The Greens are talking about starting a conversation about a plan to make houses more affordable. Where have they been? They don't need a plan to compete with Labour's plan on affordable housing. There wouldn't be a single aspect of Labour's policy that the Greens disagree with. There is no need for them to muscle in.
Imagine the Greens' response if Labour launched a major Swimmable Rivers campaign to compete with the strongly branded Greens one? The parties should start thinking about policy areas of common agreement in which one of them might take a back seat. Turei may have told the truth as she saw it but for someone who has been a party leader for seven years, it was careless and damaging to her party and to Labour.
Todd McClay's failure to tell the truth reflects badly on him as Trade Negotiations Minister rather than his party. He has held that job for only six months but he has been a minister for three years.
He mishandled a media story that floated the notion of a trade war by the Chinese Government with New Zealand in retaliation against a possible inquiry into Chinese steel imports. It turns out that he and his officials had had enough information since the end of May to cast doubt on it. But he gave the story legs by denials about the Government then two different admissions as to what he knew and when.
McClay gave answers to questions that may have been technically correct in terms of a Chinese Government trade war but were misleading in terms of what he actually knew about comments made by a Chinese importer.
The Opposition tried to paint the political failings of the minister into a story about the failure of the Government to take threats of a trade war seriously. But the facts did not support the claim. Key himself had been kept in the dark by McClay.
Being publicly castigated by the Prime Minister and forced to apologise will be a lasting blight on his career. If in doubt, tell the truth, the whole truth.