NZDF told its new Minister of Defence Ron Mark it believed "collateral damage would be minimal" when it undertook the controversial NZSAS raid in 2010.
It was a striking statement after six years of denying or playing down the possibility of civilian casualties.
Now NZDF appeared to be telling Mark that it was always possible civilians would die before the first shot was even fired.
New documents released through the Official Information Act show that NZDF then went on to publicly release different information.
It then had to tell Mark a mistake had been made and it actually meant to say, the documents show, that it believed "collateral damage would be avoided".
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The truth of the Operation Burnham raid is soon to be explored in a public inquiry into the NZSAS operation which NZDF says led to be the deaths of nine insurgents.
This latest factual fumble by NZDF comes after a cluster of stumbles, including that no photos of the mission existed even though it had publicly released three images, that no more photos existed when they did - and that the denial of possible civilian casualties was a misunderstanding it could have corrected earlier.
NZDF is under intense scrutiny over allegations in the book Hit & Run - by Nicky Hager and Jon Stephenson - that the raid caused the deaths of six civilians and injuries to 15 other people.
Mark said he was made aware of differences in the information provided in a "draft version of an information pack" and the version which was released publicly.
"The Defence Force have advised my office these changes occurred as officials reviewed and refined the final document.
"They have told me their intention was to remove inaccuracies contained in the draft version."
Mark said he was not told of the changes before the information was made public but had been told it would not happen again.
It came after the Office of the Ombudsman reviewed information held by NZDF on Operation Burnham and found it could be more forthcoming to those seeking details under the OIA.
Mark's office was provided with a copy of what was to be released and he was to be told - along with the Prime Minister's office - when the new details would be public.
The documents show Mark's office was alerted at 11.42am on March 7 the new information had been published on NZDF's website.
Just an hour and seven minutes later, Mark was briefed by his staff over discrepancies in the information. The documents show an adviser had compared the document and then asked NZDF to "please explain … as we had no indication that there had been changes to the information pack".
The shift in language around collateral damage - from "minimal" to "avoided" - appeared the most significant change, although other changes emphasised the lack of awareness among the NZSAS of aircraft fire hitting buildings that may have contained civilians.
An NZDF spokesman said Mark's office was given a "working document that had not been checked or peer reviewed for accuracy at that stage".
"Subsequent to more work being done and the answers being checked, a number of corrections were made to ensure the accuracy of the document before it was publicly released.
One of those corrections was the language around collateral damage. The initial statement was inaccurate, and was amended before final release because it was inaccurate.
"The statement released that 'collateral damage would be avoided', is correct."
National's defence spokesman Mark Mitchell said the process sounded "sloppy" at a time when NZDF needed to ensure it was providing accurate and timely information.
Mitchell, who has worked in war zones, said phrasing around collateral damage as something to be "avoided" described the ideal situation. The term "minimal" was more realistic, he said.
"It's an environment in which you can't control everything."