Ms Burch and Education Director-General Diane Joseph carefully described how a 10-year-old boy with autism had been placed in a cage-like structure in a Canberra school.

This so-called serious complaint was quickly understood for what it really was: a fundamental failure by the education system.

The two-metre by 2m cage, made of blue pool fencing and designed to be a withdrawal space, was built in a room adjacent to a classroom on March 10. It was dismantled on March 27, a day after directorate officials became aware of its existence.

Costing more than $5000, the cage had a roof, a self-closing door and a latch.

Despite any semantics, the cage represented a failure in care for a child with disabilities and his family, and a possibly career-defining error of judgment by a school principal who was placed on administrative duties.

It again raised questions about the performance of Ms Burch, the latest of high profile controversies connected to her portfolio.

Urging caution on reporting about the matter, Ms Burch said the government was being careful not to release personal information about the child or the school.

She launched an independent investigation and said a report was expected within weeks.

If there was any strategic intent of minimising media coverage by announcing the incident a day before the Easter long weekend, it backfired. April 2 is World Autism Day, significant for advocates and families and growing awareness.

Revelations about a boy in a cage sent the story around the world.

A second review was announced in early May, considering how schools deal with challenging behaviour. Led by Professor Tony Shaddock, it was to consider complex needs students and at the use of "exclusionary withdrawal".

By the middle of June, confusion remained over the status of the cage inquiry. Ms Burch's own deadline had long passed but the Assembly was told key people were on leave. The same day, the inquiry was said to be "close to conclusion".

On June 18, with 10 weeks already passed and facing more criticism from school parents, there was still now report.

Ms Burch set a new deadline of three weeks as Australian Education Union ACT secretary Glenn Fowler described the government's initial response as unrealistic.

Facing growing criticism, Ms Burch refused to answer questions in Estimates hearings about who had authorised the cage, who had built it and how it was paid for. She accused opposition education spokesman Steve Doszpot of using the affair as a "political football".

Again in June the report was said to be "close" but it was not released as July came and went.

Ms Burch eventually sought to move pressure onto directorate boss Diane Joseph in late August, saying she had strong concerns over the delays.

On Tuesday, five months after the cage was first announced, a tense press learned of the report's findings. The principal had lost her job after being identified as the sole instigator of the cage.

She would not return to lead any school. She had paid for the cage with school funds and no one in the directorate had given any approval.

Ms Burch said she retained confidence in Ms Joseph's leadership and took ultimate responsibility for what happened in schools but said neither would resign.

The message was the principal had been exclusively at fault.

Bureaucrats still face sanctions after failing to act on the first advice about the cage in March, including not appropriately escalating concerns from families. Ms Joseph refused to say how many public servants were being disciplined or if any would lose their jobs.

After 165 days, Ms Burch conceded the system had "sold Canberra families short…and it will never happen again."

She returned to attack mode a day later, criticising The Canberra Times for publishing the shocking photo of the cage, claiming showing the public what had happened inside a Canberra school amounted to a violation of the privacy and dignity of the child and family members.

Her office confirmed Ms Burch had seen a photo of the cage before it became public, but it was in black and white and taken from a different angle.

Another photo emerged on Friday, appearing to show a child inside the cage which was under a sign described it as a "sanctuary".

Since the government was renewed under Andrew Barr less than a year ago, Ms Burch has faced criticism in political circles and the media. Now a year from the election campaign, her performance is under close scrutiny.

Weeks after Simon Corbell called time on his own political career, she will seek to avoid more controversies. For the government, this week the cage once again became an "inappropriate structure". This was an "isolated incident" and the actions of "one individual".

The Assembly returns on Tuesday and Ms Burch remains a clear target for the opposition.