Julian Stacey escaped from Garden Court, run by Spectrum Care, in Mangere on February 7, 2010.
That afternoon Julian, who functioned like a 2-year-old, was found drowned in a pond about 200 metres away, having escaped the facility through a gate.
Emergency services were alerted by Julian's mother Natasha Stacey about 3pm that day. She told the 111 call-taker that her son couldn't communicate.
At an inquest in Auckland, Coroner Peter Ryan said his impression was the call-taker was "properly appraised" by Ms Stacey. He asked the officer in charge of the inquest, Sergeant Sascha Huff, if police initially treated it as a serious matter.
"No we didn't," Ms Huff said.
Shortly after Ms Stacey's call a Spectrum employee, Vijay Naidu, made another call to emergency services reporting the disappearance.
She told the 111 operator Julian had normal functioning. Ms Stacey's lawyer Moira Macnab asked Ms Huff how the police response would have been different if officers knew information such as Julian was severely autistic, liked water and had no sense of road safety.
Ms Huff said such information would have been "helpful".
"I think there would have been a sense of urgency, certainly. We do get reports of missing children often, however, Julian was not a child that simply had not come home from school or had escaped from his home. He was in a care facility and had severe autism."
Ms Macnab said Julian's family would be asking the coroner to make recommendations about the type of information respite care workers should give to emergency services in such situations.
Ms Huff said the two police officers who were sent to search for Julian would be able to give evidence about what they were told by the 111 call-taker.
Mr Ryan also asked Ms Huff why the police officer who found Julian in the pond didn't remove him straight away, and instead fetched a camera to photograph him.
Ms Huff said that was a departure from police best practice of trying to preserve life above all else, unless it was obvious a person was dead.
The two police officers have interim name suppression.
Several members of Julian's family, including Ms Stacey, are at the inquest, which is expected to finish tomorrow or Wednesday.
- By Jimmy Ellingham of APNZ
