He was hospitalised with two black eyes, a sore hand and significant bruising.
Stressed and anxious, the man returned to work in the same unit nine days later, with the same inmates who knew about or had witnessed the assault.
His life started going downhill, the Employment Relations Authority (ERA) would later hear. The officer started to take numerous sick days, had trouble sleeping, and other violent prison incidents triggered flashbacks.
"He perceived comments by other Corrections officers as meaning the assault was his own fault," the ERA said in its final decision.
Transfers to other units didn't work and it was not until September 2013, a little over a year after the assault, that the Department of Corrections referred him to counselling.
In January 2015, he was placed on leave for medical reasons and, later that month, received a letter from the department confirming that he was to attend a medical assessment to determine whether he could return to work.
"This decision was taken without prior consultation with him. It left him believing that the department was exploring whether he could be dismissed and he felt betrayed," the ERA noted.
A claim for ACC cover and compensation for post-traumatic stress disorder (PTSD) caused by the assault was assessed and declined.
Receiving the news led to an extremely distressing episode for the prison officer, attempting to take his own life four times and spending a month in compulsory detention at Wakari Hospital, a psychiatric facility in Dunedin.
On October 5, 2015 he accepted an offer of medical retirement having been deemed unfit to return to work – and his ACC claim for weekly compensation was reviewed and accepted in January 2016.
And although the prison officer has found new work as a labourer, life is still a struggle.
"He has suffered significant personality changes describing himself as two persons: the one who existed before the assault and the one who exists now," the ERA says.
"Having completely lost the former version of himself, he described feeling like he is living a nightmare; having gone from a functional, contented man, happy in his job with good professional and personal relationships and financial independence to a person who has lost all of those things. He described himself as 'a man broken into a thousand pieces'."
In 2018, the ERA found that Corrections had failed to take practical steps to stop the assault and help the guard deal with his resulting mental issues.
At the time, the ERA ordered $30,000 compensation, which was challenged by the ex-prison guard's lawyer.
Now, the ERA has accepted it made an error and has ordered Corrections to pay their former employee $65,000 for breach of contract.
