Gallipoli was stuffed-up in both planning and execution. That meant a big cover-up. So many things had been mishandled during the launching of the attack that it's a wonder even more troops weren't killed.
The cover-up went as far as communicating misinformation to the Australian Government who didn't have a clue what was happening in the Dardanelles.
The break came when an enterprising Australian journalist, Keith Murdoch -- a brilliant reporter and a better man than his son Rupert could ever hope to become -- got news through to Canberra about what was really happening,
That resulted in the Australian Governemt (Australia had, at that time, been a self-governing country for only 15 years and was afforded no respect by the British ruling class) demanding a role in the decision-making. They insisted that the withdrawal, which was expected to cost thousands more lives, should be under the command of Australian, rather than British, officers. The retreat was so effective that it was accomplished with virtually no loss of life.
So there was a cut-off point in how it was portrayed -- AM AND PM. Which is to say, ante-Murdoch and post-Murdoch.
Until Murdoch's revelation the Australian government and the press were told nothing but lies. After that the truth became known, although, of course, much of it was not told until after the war.
Australia and New Zealand came of age at Gallipoli. It was a glorious defeat which many would equate with the slaughter of Colonel Travers and his heroic band at The Alamo.