That was probably wise. His colleagues did not need a lecture. What they wanted was reassurance.
They would have wanted answers to three questions: why are things suddenly turning to custard for National; what on earth is going to happen next; and, what are they going to do about it.
National is floundering. It may turn out be a temporary aberration - Mr Key will call on every device in his political repertoire to ensure it is.
But right now it feels as if the political gods are bored with the widely held assumption National will cruise to victory in September's general election. Someone or something has torn up National's script which was supposed to guarantee the party safe passage through to polling day.
That plan was designed to take advantage of a series of events in the countdown to the poll.
These included the prime minister's trip to China in March; April's media feeding frenzy courtesy of the future King George VII and his mother; next week's likely unspectacular but responsible Budget; and, an as-yet-to-be-confirmed prime ministerial visit to the White House.
These election-year distractions would keep the media focused anywhere but on Labour, thus starving it of the oxygen of publicity. National, meanwhile, would project a business-as-usual image of a safe governing party, such that there would be little for voters to get excited about and continuity would be the name of the game by the time election day arrived.
But things have suddenly gone horribly awry for National. Two experienced ministers have fallen from grace having exhibited all the classic symptoms of Beehive arrogance and born-to-rule Tories.
The party now finds itself being smacked around by an Opposition campaign highlighting some of National's highly questionable fundraising techniques, most notably ''cash for access'' to a minister and the party's shadowy ''Cabinet clubs''.
The prime minister may well argue he is highly accessible across society regardless of how often his time is put up for sale at National's fundraising dinners.
He can warn the costs of fighting elections mean the only viable alternative to such fundraisers is state funding of political parties.
None of that rationalising of ''cash for access'' makes people any more comfortable with a practice which allows those with money to buy influence in government circles.
The politicians can argue there is no quid pro quo for such donations. The public, rightly or wrongly, believes otherwise. People feel equally uncomfortable about National taking money from Chinese nationals whose culture is much more explicit about reciprocal obligations on those who accept donations.
However, no political party can claim the moral high ground in any argument about political donations.
Mr Key hammered that point in Parliament on Wednesday afternoon, catching Labour off guard by revealing it had its own version of ''cash for access'' which enabled party members to meet an MP of their choice in return for a $1250 donation.
But this is small beer compared with the sums National has been charging for access to Cabinet ministers. Moreover, those ministers have the power to change things.
However, of most significance is that ''cash for access'' is a complete about-turn on the standard practice of ensuring politicians do not know the identity of the source of large donations. If you are prime minister, then you know the person sitting next to you at a fundraising dinner has paid handsomely for the privilege.
National is getting its comeuppance, however. Mr Key might have wiped the floor with his opponents on Wednesday but he was away from Wellington on Thursday when the Opposition comprehensively mauled National.
Mr Key's headache is that all this is feeding neatly into David Cunliffe's ''cronyism'' narrative which seeks to paint National as only helping its rich mates.
But it is an open question as to what degree Mr Cunliffe's ''cronyism'' line is gaining traction with voters. One of the reasons Ms Collins has survived the axe is because there is no groundswell of public opinion demanding she be cut adrift.
She is very damaged goods, however. Labour and New Zealand First may not have secured her head on a platter, but that is a mere technicality.
The two Opposition parties can feel well chuffed with their detective work as they sought to entangle Ms Collins, her husband, the milk exporting company Oravida and China's border control in a web of alleged corruption.
They have so far failed to prove Ms Collins has benefited financially from an obvious conflict of interest to which she initially purported to be oblivious.
But that failure barely matters now. The hounding of Ms Collins has produced another, arguably more useful dividend. The pair have spiked one of National's best weapons. And not only that. Rather than causing trouble for National's enemies, the Justice Minister has instead become a source of aggravation for her own political kin.
Mr Key is punting on a few (Twitterless) days of stress leave seeing Ms Collins coming to her senses.
Mr Key and his senior colleagues must be dreading what might happen if she does not. That, and the need to avoid doing anything to puncture caucus unity and morale little more than four months out from election day, is one reason why Mr Key will not sack Ms Collins from the Cabinet unless solid evidence emerges.
On that score, Winston Peters says there is ''more to come''. But, as National's Gerry Brownlee told Parliament, Mr Peters always says there is ''more to come''.
Mr Brownlee's colleagues will willingly bow to his experience because for the past two weeks National has lost control of the political agenda.
This Thursday will see the delivery of the Budget. Normally, that document is an agenda-setting device. However, if this year's specimen turns out to be as low-key as its advance billing, then it will not be setting anyone's agenda. Such is National's current misfortune.
- John Armstrong is the political correspondent for The New Zealand Herald.
