At this point in time that is entirely new information. Could you please give us a source for that? Thank you in advance.
Downer gave an interview on Australian television a couple of weeks ago about this. That interview matches what I've heard from a number of different sources. It also matches common sense.
His Excellency the Honourable Alexander Downer, Companion of the Order of Australia, Ambassador Extraordinary and Plenipotentiary, High Commmisioner of the Commonwealth of Australia to the United Kingdom of Great Britain and Northern Ireland, is not going to be somebody who is used to entrap a young lawyer, working as a minor adviser to a Republican Presidential candidate. Downer isn't an intelligence agent - he's way too high profile for that including his time as Australia's longest serving Foreign Minister (equivalent to your Secretary of State).
What happened is fairly simple - Papadopoulous was friends with somebody working at the Israeli embassy in London. That man was the boyfriend of a relatively junior staffer at the Australian High Commission (the two are now engaged). He introduced Papadopolous to his girlfriend and when Papadopoulous found out where she worked, he asked if she could arrange a meeting between himself and the High Commissioner Alexander Downer. He said he worked for Donald Trump, who was that stage likely to be the Republican nominee and therefore was potentially a US President. On that basis, Downer agreed to meet with Papadopoulous on the grounds he might be a useful person to know.
The Australian High Commissioner does not go trawling for people to talk to. That doesn't make any sense.
At the meeting, Papadopoulous - for whatever reason - told Downer the Russians had some sort of compromising information concerning Hilary Clinton. He knew who he was talking to - the representative of the Australian government in the United Kingdom. If he did not expect that information to be passed back to Canberra, he would have to be an absolute moron.