Staff met with the boy's carers but there was no formal investigation into the complaint and the DHB did not inform the boy's parents of the carers' complaints and actions taken in response.
Throughout 2010, the boy's parents remained concerned about the care he was receiving.
In August that year, one of the boy's carers informed the parents of two incidents where he witnessed the team leader physically and verbally abuse the boy.
The parents complained to police and the National Health Board. Following the complaint to the National Health Board, the DHB conducted an investigation. The investigation was paper-based. No staff were interviewed, and the parents were not involved in the investigation process.
The review concluded that the complaints were not substantiated.
A subsequent review conducted between August 2011 and April 2012, which involved staff interviews, found there was a high probability that the team leader had physically and verbally abused the boy.
Mr Hill found it was more likely than not that the team leader was physically and verbally abusive towards the boy, and that her behaviour was intentional, direct, and repetitive.
"In particular, there is strong and compelling evidence that she kicked him, pulled his hair, and was regularly verbally abusive toward him," Mr Hill said.
The team leader's behaviour towards the boy was a serious departure from the expected standard of care and showed a flagrant disregard for the boy's rights.
"There can be no excuse for such behaviour. This is far from what we are entitled to expect from disability services in New Zealand," he said.
Mr Hill found that the DHB's response to the concerns raised about the care provided to the boy fell well short of the expected standard and put the boy's safety at risk.
While it was not wholly unreasonable for the National Health Board to rely on the response provided to it by the DHB, the parents had raised very serious concerns about the care being provided to the boy and the National Health Board's view on the adequacy of the DHB's response to those concerns was based on very little information, he found.
The team leader and the DHB were referred to the Director of Proceedings for the purpose of deciding whether any proceedings should be taken. The director was yet to make a decision on this case, Mr Hill said.