An Oranga Tamariki report that recommended loosening the bail conditions on a violent offender did not include anything about his long history of assaults and intimidation, an inquest has heard.
The man was allowed back to the home of a woman he had briefly lived with before, and her toddler son was found dead just days later.
The man was charged with murder but found dead in custody shortly after.
The inquest in Wellington also heard that after the boy was taken to hospital multiple times, where he was found to have an an explained fractured leg and other injuries, no safety plan was completed before the boy was discharged from hospital back to the home - despite the plan being demanded under safety rules.
"Yes, I think an opportunity was lost" to set up safety measures, an OT manager told the inquest today.
It heard that Oranga Tamariki - then called Child, Youth and Family (CYF) - did not even know the judge had varied the man's bail till days after it happened.
"We didn't know," the manager said.
A coroner is hearing evidence about the role of state agencies - CYF, police, Corrections and a health board - in how the man came to be alone with the boy the day before he was found dead in bed, his vertebrae crushed.
The coroner heard that CYF and Corrections had a series of reports detailing the man's violent past, and that said he was considered at "high risk" of repeating his violent behaviour against his new partner, the boy's mother.
Yet when a judge asked CYF for a fresh report on whether to vary his bail, a social worker reported back that CYF "would have no concerns" about the man being on electronic bail at the home.
This crucial report had nothing in it about his history, or how he was not allowed to see his own children.
It was also "silent" about the man emotionally abusing his own children, a lawyer for the boy's mother told the inquest.
The manager who supervised the social worker who did the report, said she could not recall if she asked for the concerns about emotional abuse to be included in the CYF report to the court about bail.
Asked if she had any concerns about the man being allowed into the home, she said, "Only in as much as how would we make the safety plan work".
She said the man did not have history of sexually or physically assaulting his own or other children, and that he had lived with the woman briefly before "without reports of concern".
However, she also said given the man's history, there was certainly a question mark over whether it was suitable for him to be there.
The crucial CYF report mostly consisted of interviews with the man and the mother, unverified by others.
The manager said she discussed the report with the social worker, but did not give her an assessment plan beforehand - though it had been documented that she did - and that she was away when the report was finalised for the court.
The manager said though CYF recommended to the judge that the bail be varied, it was not alerted by the court or Corrections when this actually occurred.
Confusion was exacerbated because CYF did not usually have a role in district court proceedings, and because it was usually up to Corrections to assess an offender's risk.
"It was a bit of muddle … exactly what we were trying to do," the manager told the inquest.
CYF only found out the man was at the house when, a few days later, it was called to the hospital to help plan the boy's safe discharge. He had been treated for multiple, unexplained injuries including a fractured leg, a missing tooth, bruising and crushed fingers.
The hospital admitted in a previous inquiry that it let him down.
"The system failed with tragic outcomes" for the boy and his whānau, a Health and Disability Commissioner report said.
A police officer earlier told the inquest that a safety plan had been done. He did not see it, but there there were a lot of conversations about it, the officer said.
But the inquest was told today there was no such safety plan.
There was also no multi-agency discharge meeting, though this was also required between police, CYF, and the hospital.
The OT manager agreed at the inquest a proper plan could have engaged the boy's daycare, other support agencies and people popping by the house, in a proper safety framework - but did not.
An executive summary from a 2017 OT review of what went on, said the guidelines were clear and strong enough, but OT practice was not.
"Roles and responsibilities were not clear and follow-up tasks and monitoring was insufficient," it said.
The OT manager in the inquest alluded to the 2017 finding that they had adopted a "rule of optimism" instead of a "rule of caution".
The executive summary also found the way CYF prepared its report to the court was "ambiguous and unclear".
"It did not contain sufficient critical analysis of the potential risk factors," the summary said.
The OT manager said the CYF office was short staffed and things were "very very stressful" at the time.
She needed six staff but had between two and four on hand.
It was not her preference to give the job of doing the crucial report to the social worker who did it - though that person was experienced - but she'd had no choice.
At the hospital, she had to put herself into a key role in order to meet a 24-hour deadline too - even though she did not intend to act in that role.
"The site constraints were such that there was not an available social worker at that moment," she said.
The executive summary from OT in 2017 said: "Whilst agencies and individuals ... 'shared' concerns, there was less evidence of them sharing responsibility".