Premier Jay Weatherill admits the Education Department made another mistake in claiming there was no record of a meeting he had at a school where a girl was sexually assaulted in 2010.
The Premier attended a meeting at the school in Adelaide's north-western suburbs in September 2011 to discuss amalgamations when he was Education Minister.
Briefing notes released under Freedom of Information show he was not notified about the rape prior to his visit.
Opposition frontbencher David Pisoni requested the paperwork last year but was told no such record existed.
The Department told Mr Pisoni on Monday that a document had since been found.
An independent inquiry by retired Supreme Court judge Bruce Debelle is currently being held into the Government's handling of sexual abuse cases in schools.
Premier Jay Weatherill says he is unhappy about the Department's mistake.
"The Department have clearly made an error," he said.
"The error was corrected quickly and it vindicated the remarks I made publicly.
"There have been a number of errors made by the Department and this was another one.
"We will await the outcome of the Debelle report and act on its recommendations.
"I found a Department that had I believe problems with its culture. That's why I changed the chief executive of the agency and it's disturbing that we still see some of these difficulties."
Mr Weatherill is currently preparing for a major cabinet reshuffle after senior ministers Patrick Conlon and John Hill announced they will move to the backbench and not seek re-election.
He rejected suggestions he is waiting for the results of the Debelle inquiry before deciding on ministerial appointments.
"We will continue to do the work of Government," he said.
"I will make judgments about the composition of my cabinet based on what is in the best interests of South Australia."
Mr Pisoni says the discovery of the document after the earlier denial of its existence casts doubt over the Freedom of Information process.
"It wasn't until the Department received a request from the media that within three hours the document was found and I was notified in a change in the determination of the request," he said.