Guards who could not rouse a prison inmate lying near death in his cell following a brutal attack then sat filing paperwork and eating sandwiches for 20 minutes, a prison inspector's report says.
The full extent of the failings that endangered inmate Benjamin Lightbody in May 2013 have been revealed in a prison inspector's investigation of Mt Eden remand jail, which was run by Serco at the time.
Mr Lightbody suffered extensive brain damage in the attack and plans to sue Corrections for failing to keep him safe.
The report, which Mr Lightbody received under the Privacy Act and passed on to RNZ, shows an ambulance was not called until more than two-and-a-half hours after the unprovoked attack.
It said he was in the gym yard when an inmate with a pool ball in his fist smashed him in the side of his head because he would not hand over nicotine patches.
The inspector found other inmates witnessed the attack, but did not help, and no guard came.
Mr Lightbody eventually staggered to his cell and collapsed on his bed.
Nearly two hours later an inmate posted a note to the guards' glassed-in base, saying, "Newbie in cell 4 knocked out by cell 5. I told you this would happen!"
A guard then checked on Mr Lightbody and found him totally unresponsive despite shaking him and shouting at him.
Both guards did nothing else initially. They sat at their base for 20 minutes, with one continuing to file while the other made himself a hot drink and ate a sandwich.
During this time, the prison wing's manager and supervisor left the unit. The supervisor told the guards that he was off for the next week and that it was up to them to "sort it out", the report said.
The supervisor denied being told of the assault.
Nurses were finally called, but the first arrived without an emergency first aid kit.
An ambulance was eventually called at 5.02pm, more than 2 hours 30 minutes after the attack, arriving 11 minutes later.
The chief inspector said the delay in calling an ambulance was "excessive", "unacceptable" and "unexplained".
The report also revealed Mr Lightbody had told guards just before the attack that he had been threatened, but they did nothing about it.
The attacker was also free to walk around the prison for more than two hours afterwards, as his victim lay in his cell. He was later convicted and received extra prison time.
The report said a root cause of the attack was understaffing.
Usually only two guards were on duty in the wing and an officer told the inspector that staff "felt very unsafe" in such small numbers.
The inspector listed a stack of failures, including poor record keeping, poor risk assessments - which meant seriously violent prisoners were kept in units they should not have been - and inadequate medical care.
Mr Lightbody said Corrections and Serco had both told him this report did not exist - something Corrections disputed.
The department now faces legal action from the Office of Human Rights Proceedings for failing to give Mr Lightbody a video of the attack.
The chief inspector recommended an employment investigation of guards and the supervisor. A member of staff was dismissed.
Corrections said it withheld $160,000 dollars from Serco in the 2012/13 financial year for missing targets.
However, the department continued to rank Mt Eden as exceptional in its prison performance measures when the jail was under scrutiny over the safety of inmates and staff. These ratings were later overhauled.
Serco lost its contract to run Mt Eden after fight clubs at the prison were revealed, and resisting attempts by Corrections to improve poor supervision and understaffing.
It runs South Auckland prison, which Corrections recently ranked one of the worst performing prisons.