Brownlee abruptly terminated an exchange with journalists outside National's caucus room on Tuesday morning, sarcastically observing that a reporter's supposed source was bound to know more about readying military personnel for deployment to Iraq than he would as Minister of Defence.
He made a similar quip to NZ First's Ron Mark, saying the MP's sources in the Defence Force were getting a bit long in the tooth to still be reliable.
Yet Brownlee ended up more or less confirming what Mark was claiming - that personnel at the Waiouru army camp was already preparing for deployment as a contingency, should the Cabinet give the big tick to sending a unit of military trainers to ready Iraqi troops for combat against the jihadist forces of Isis.
The real surprise would have been those trainers not doing advance preparation in anticipation of the Cabinet decision.
Moreover, no decision can be made until an advance planning team returns to New Zealand with logistical detail such as exactly where the training unit will be located and so forth.
The puzzle is why Brownlee did not simply declare all this upfront. It was hardly a state secret. He would have saved himself a lot of bother.
When he picked up the Defence portfolio in John Key's post-election reshuffle, Brownlee could have been excused for thinking his new responsibility would be a comparative doddle when lined up against his other principal role of Earthquake Recovery Minister.
His new role could end up being just as nightmarish and even more thankless.
Brownlee's state of mind may well reflect increasing angst within Government ranks about the political risks in such a deployment, which will far outweigh any impact on the fortunes of Isis.
The fact is that there will be precious little upside and an awful lot of potential downside. That was not so obvious a month ago when the Prime Minister set out the options for New Zealand's contribution to Operation Inherent Resolve -- the name the Pentagon in Washington gives to the United States-led intervention in Iraq.
Key played things very cautiously, ruling out sending any combat soldiers and making that a bottom-line. He also stipulated that the training personnel would be operating "behind the wire" for safety's sake.
The closer the Cabinet gets to a decision the more questionable it seems that such a deployment becomes.
The biggest question is why bother. New Zealand's contribution will be token. It always is. But it allows the United States to run another country's flag up the pole, thus adding more legitimacy to the overall operation. Or so the Americans would like to believe.
Of more pressing concern is that any attempt to lift standards and morale in the Iraqi army is close to futile given the rampant and endemic graft and corruption in senior ranks exposed by the New York Times last month.
The revelations should make Key's and Brownlee's hair stand on end -- as should the statement that the Americans do not see it as their role to do anything about it. Then there is the bitter rivalry between Shiite and Sunni, which has resulted in the gutting of the high command of Iraq's armed forces.
Labour argues Key consequently is unable to make the case for the deployment. Labour is wiping its hands of the whole business - thereby leaving National without the valuable cushion of bipartisan support should some of those deployed end up coming home in body bags.
Labour judges there is already precious little public enthusiasm for this foreign adventure. But there is another reason why Labour is not keen.
A ghost is stalking Wellington's corridors of power. It is the ghost of Anzus - the now forgotten post-World War II defence pact which obliged Australia, New Zealand and the United States to come to one another's assistance if under attack.
It is not a welcome apparition. "Anzus" is a dirty word in New Zealand's domestic politics. It signifies the era when Wellington kowtowed to Washington, London and Canberra without question or hesitation.
It was an era which did not really end until the mid-1980s and Labour's promulgation of its anti-nuclear policy. That saw New Zealand briefly treated as something of a pariah in those overseas capitals. The by-product was a more independent foreign policy -- or at least the perception of independence. The Labour Party wants to believe that is still the case even if no one else does.
One of the few advantages of Opposition is that there are no ugly compromises to be made which dilute that independence.
It is a very different story in Government - especially when Uncle Sam comes knocking at the door for assistance.
New Zealand always complies. That is the deal.
Even Helen Clark was forced to succumb to the pressure from Washington and sent two teams of military engineers to Iraq in the wake of the Anglo-American invasion which ousted Saddam Hussein.
For its part, National cannot ignore the legacy of the anti-nuclear policy. That was evident in Key's delayed and ultimately limited offering to the Americans when compared to the bounty offered up by Tony Abbott, his transtasman counterpart -- a training team compared to fighter bombers and 200 elite SAS soldiers.
Key and Abbot have floated the possibility of an "Anzac-badge" joint Australian and New Zealand training unit being sent to Iraq to participate in Operation Inherent Resolve. It would seem the good old days of Anzus are back again - at least on the right. While tackling Isis is a priority, the speed with which Abbott offered up gifts to the Americans will leave Labour wondering what room there is for New Zealand's independent foreign policy in such cosy arrangements.
In ruling out a combat role for New Zealand troops, Key was clearly hoping to have Labour on board. But Labour's new leadership has already tested the patience of the wider party by agreeing to vote in favour of amended anti-terrorism legislation currently before Parliament.
National's training mission may have been so designed to make it easier for other political parties to stomach. But there was just too much for Labour to swallow first.