Authorities have defended their actions, saying people are innocent till proven guilty and the man's bail conditions prevented him having unsupervised contact with children.
However, both the watchdog and the man's employers now admit they didn't understand the seriousness of his offending and could have acted sooner to suspend him with more information.
Legal rulings prevent him being named and his occupation is suppressed.
Now in his 40s, he abused his stepdaughter for four years while she was aged between 8 and 12 before she confided last year to a school counsellor, who immediately alerted police and Child Youth and Family.
But even after being charged with a raft of sex crimes, including the attempted rape of a minor, his professional license was renewed last December on appeal and he was allowed to continue working in his profession this year.
His license had earlier been cancelled by the watchdog after a police vetting report revealed his criminal charges.
Meanwhile he worked part-time this year at a facility that allowed him contact with under-19-year-old girls.
Though the facility also hosts children's birthday parties, its owner says the sex offender worked in a separate area, and that justice officials were "comfortable" with his role.
The owner admitted being unaware about the extent of the man's charges and "probably" wouldn't have employed him with the benefit of hindsight.
"He did a good job. He never caused me any reason for concern.
"He's going to get locked up for a while. Let him serve his time and he may get a second chance."
The victim's mother is furious authorities let the man continue working with the public, saying his profession's watchdog "dropped the ball".
She told the Herald she arrived home in June last year to find police and CYFs officers waiting on her doorstep.
"They sat me at the table and said, 'I need to tell you your daughter has just gone to the school counsellor and we have been informed that she is no longer safe and has been sexually assaulted'.
"I was pretty much numb. It was just monumental shock. I thought I had been vigilant in keeping my children safe."
She was told to remove the man from her house or her children would be taken into foster care.
He moved cities and was hospitalised after attempting suicide.
Despite being under police investigation, the man obtained professional work with another employer, plus work at the facility.
The victim's mother said her daughter became withdrawn following the abuse. The last 17 months had been "soul destroying".
"I hope now that my daughter can heal and look forward to living the happy life she deserves. He stole a third of her childhood, that is heartbreaking and unforgivable.
"He made those decisions and he must now face the consequences."
Detective Steve Wilson said he personally notified both the facility and professional watchdog about the police investigation.
"They were certainly aware of the charges and particular bail conditions."
Asked if he considered it appropriate for the man to continue working while awaiting trial on sex charges, Wilson said: "As a member of the public, I can see both sides, however safeguards were put in place to protect the wider public."
In a statement, the watchdog said immediate action was taken against the man this week following his convictions.
"Public health and safety is always an important consideration however there is a legal presumption that a person is innocent until proven guilty."
The watchdog could apply to suspend someone's license in serious cases.
But it said the full extent of the man's offending had not been understood as the watchdog did not have access to the Crown's summary of facts.
It "sought but was not provided with sufficient information to allow it to exercise all of its available tools".
The man's professional boss said he was terminated about two months ago when the seriousness of his charges came to light.
"He didn't share as much as he probably should have. It's disappointing.
"It's sad for the victim and her parents. It's gutting for them."
