Three long-serving Royal New Zealand Air Force staff were put under intense scrutiny after a string of investigations into their connection to a company carrying out work that potentially saved the military's reputation.
The formal investigations into Miltech Ltd and those associated with it included going through one air force sergeant's bank records, power bills and private property after defence bosses told their minister the matter was being questioned by an Opposition politician and media.
Their inquiries found little misconduct, and no grounds for complaint about Miltech or its work, beginning with an emergency effort in February 2014 to save the navy from embarrassment over its lifejackets.
Instead, internal inquiries and an Auditor-General's investigation found fault with Defence Force processes and its ability to follow its own rules in hiring Miltech.
Documents obtained through the Official Information Act show Miltech was hired amid a faltering system for servicing lifejackets which began in 2011, when NZDF was moving 1400 staff out of uniform in a cost-saving exercise that was also aimed at having a greater proportion of military staff in front-line roles.
The documents include a report from military experts at Strategic Sourcing after concerns about the amount of lifejacket work the air force was sent by the army and navy.
The report said the air force had been made responsible for all lifejacket maintenance in 2011 despite "the absence of a fully developed business case".
As a result of a "misunderstanding", the number of lifejackets needing to be serviced was miscalculated. "An overestimation of capacity was exacerbated by an underestimation of volume for both the navy and army".
One example cited in the report showed the air force serviced more navy lifejackets in three months than defence bosses expected to be done in an entire year. And even though the air force expected headquarters to send more staff, defence bosses believed more staff were not needed because there was "spare capacity".
At the same time, a number of specialist staff who serviced the jackets left the air force.
"The overall lack of experience, however, places a significant training and supervision burden on the more senior personnel."
The report also revealed that lifejacket servicing cost NZDF very little - $300,000 in staff hours each year from an overall defence budget of $3 billion in 2014.
An NZDF spokesman said there was no miscalculation in the number of lifejackets needing to be serviced, but there were not enough people to do the work.
The spokesman said NZDF now had standardised lifejackets across the forces. The air force now did its own servicing but the army and navy contracted this work out.
Also considered was a court of inquiry report into the drowning of Private Michael Ross during a training exercise in 2012 after his lifejacket did not inflate. The lifejacket was serviced by the air force but the court of inquiry found servicing was the least likely factor to explain the fault.
• In February 2014, HMNZS Canterbury had no serviced lifejackets during a major military exercise. That led to the urgent hiring of Miltech Ltd, owned by an air force sergeant who sought verbal approval for involvement in the company rather than written approval.
• Miltech missed out on a $3 million Defence Force contract during the two years of investigations into the lifejacket debacle.
• Defence Minister Gerry Brownlee refused to comment on the issue. Labour defence spokesman Phil Goff says the issues in part stem from the 2011 project to reduce "back office" staff in uniform.