Mr and Mrs Haaima did not want to talk to media after the inquest yesterday, but their feelings were reflected in a letter Mrs Haaima wrote to Mr Crerar which he received a week ago.
"Rick and I feel there is nothing to be gained by apportioning blame and we feel in no way was it the power company or the local power board employees' fault that Wayne died," Mrs Haaima said.
Her son's death had left a huge gap in their lives. "He was very much loved and is very much missed."
They "strongly urged" the implementation of a BiPAP breathing apparatus with battery back-up, which was now available.
Issuing newer machines with battery back-up would remove the reliance on the "human factor" in managing a power outage "so no other family has to go through an incident like Wayne's death again", they said.
Dunedin Hospital respiratory medicine consultant Dr Colin Wong said machines with a four-hour battery back-up were now available, but he also warned it was impossible to guarantee complete safety even if good processes were in place for the patient and family.
The machines with back-up were provided on a case-by-case basis based on need. Mr Haaima would have been eligible, he said.
Mr Crerar, in a preliminary finding, found Mr Haaima died from acute respiratory failure due to advanced Duchenne muscular dystrophy.
During a power outage, the BiPAP machine he used to breathe failed to operate as intended, Mr Crerar said.
Palmerston's electricity is distributed by PowerNet and its network operations general manager, Gary Pritchard, told the inquest a fault occurred at the substation at 3.06am on December 16, 2010.
Its control centre called out two technicians from Otago Power Services - the company contracted to maintain its power lines - and they found circuit breakers in two transformers had tripped.
Electricity was restored to all customers by 4.28am.
Mr Pritchard said there were no industry protocols for electricity distribution companies to advise medically dependent customers (those whose lives could be lost if electricity was cut to support machines) of unplanned power outages.
In cases like that at Palmerston, the priority was to secure and make safe the site, determine the fault and restore electricity as quickly as possible.
PowerNet was not aware Mr Haaima required electricity for medical purposes.
His parents believed their son's status was available to their electricity supplier, Contact.
On December 16, they did not hear the alarm on the ventilator until, they estimated, about 3.25am. When they checked their son, he was cold and not breathing. Attempts to revive him failed.