When the Australian official took to the podium to explain to reporters the discovery of satellite images that might show pieces of MH370, he carefully omitted to tell them the source.
The images were from a US satellite. The Australian Maritime Safety Authority's John Young did not mention this to the media.
When asked, he avoided the question.
And when reporters phoned Australian defence officials to ask the same question, they were given a firm "no comment" or "we can't discuss". This may seem odd, because the satellite's owners, the US company DigitalGlobe, were only too happy to tell the media.
The contrast highlights a long-standing syndrome. Australian officialdom is hyper protective of US intelligence and its sources - even more protective than the Americans themselves.
It's a symptom of the Australian defence establishment's mentality as an anxious junior ally, afraid of giving its senior partner any reason to curtail the flow of intelligence.
The use of US satellite imagery was just one part of the international co-operation involved in the 26-country search and rescue effort.
The satellite imagery of many nations has been carefully "scrubbed" by analysts in the search for the Malaysia Airlines jet, a painstaking task: "This is human eyeballs working through a vast number of images," said an official involved in the effort.
And just as quickly as Prime Minister Tony Abbott was briefed on the potential find on Thursday, he decided he should phone his Malaysian counterpart to brief him.
Pressure on Najib Razak has built cumulatively every day of the agonising 12 days of the search. He was on the phone to Mr Abbott about 1pm Canberra time, within half an hour of Australian officials requesting the call.
After Mr Abbott set out the scant facts of the sighting of potential debris in the Indian Ocean 2500 kilometres south-west of Perth, Mr Najib thanked him for the search effort and for the call. He asked to be kept closely informed of any major developments.
The Australian government has also given priority to keeping China informed. In the Australian hierarchy, "Malaysia has the primary claim on this because it's their plane," said an official, "then China because of the number of Chinese passengers, then the US because it's a Boeing."
Australia's Department of Foreign Affairs phoned the Chinese ambassador to Canberra, Ma Zhaoxu, to tell him the news before Mr Abbott rose to inform the Australian Parliament a few minutes after 2pm.
Indeed, the two countries have been considering taking the co-operation to a higher level.
Chinese and Australian officials have held preliminary discussions on bringing the Chinese military into the search.
By Thursday night, the three countries participating in the Australian- co-ordinated search were all members of the so-called Five Eyes intelligence-sharing alliance.
Australia had dispatched four Orion P3 maritime surveillance planes, New Zealand had sent another and the US had contributed a Poseidon submarine- hunting plane.
According to an official, Australia had not yet asked for any particular Chinese assets, nor had Beijing offered, but "preliminary planning discussions" had been held.
"If the Chinese have assets to put into the search, they would be very much welcomed by everyone," a senior Australian official said, potentially turning an apparent tragedy into an opportunity for a new level of co-operation.
Officials were keenly aware of two considerations. One, that if the apparent debris does turn out to be part of MH370, a long search and recovery effort could lie ahead.
"In really deep waters of the Indian Ocean, it could take years to get all the material up," said one.
Two, that it was vital to avoid leaping to any conclusions, especially after 12 days of false leads and faded hopes.
The story Missing Malaysia Airlines plane: US satellite the unspoken source that sparked search for MH370 first appeared on The Sydney Morning Herald.