He has been drawn out by frustration over a life derailed by the arrest of his current employer Kim Dotcom. The arrest on criminal copyright violation at the request of the FBI, and the subsequent court battles, have seen Mr Tempero cast in a supporting role in a drama increasingly described as being like a Hollywood movie.
He faces his own criminal charges - two shotguns bought by Mr Tempero were found on the property during the raid. In Hong Kong, he is listed as the 13th defendant. His assets, while considerably more modest than his employer's, have also been frozen.
Sitting down to speak, he says: "My whole life has been keeping people like you away from people like him."
Mr Tempero has spent large parts of his professional life away from his native New Zealand. The delight in returning foundered the day police ordered him to the ground at gunpoint. The Megaupload raid in January has soured things further with ongoing blunders over the extradition request by the FBI.
The consequence, now, is an absence of faith in the institutions he has previously worked with and trusted.
As Alinghi's former security head, he would deal with police and intelligence officials at the highest levels. Now, though, he believes the Government Communications Security Bureau has illegally spied on him, as it did on his employer.
Mr Tempero's lawyer has written to the Crown to ask if the GCSB also spied on Mr Tempero, protected through his New Zealand citizenship. The request was prompted by the Crown's admission in court the bureau had been used to track the FBI's targets for arrest and provide "any information indicating risk factors in effecting any arrest".
When linked to the police evaluation report used to approve the use of the anti-terrorist Special Tactics Group, Mr Tempero said he formed the view his location must have been part of the GCSB's information gathering. The police report highlighted Mr Tempero's likely combat and weapons training.
"Everybody has had a look at me, including our local spy people. If they didn't, they weren't doing their job.
"The GCSB's job is to check out the threat level of police when arresting Kim Dotcom. Their own [evidence] shows I was the number one threat. The affidavit shows wherever Kim was that I was.
"The spy agency's job was to assess the threat level. I believe they did."
On the day of the raid, he said "they knew exactly where I was", he says. Hearing rotor blades roaring, he emerged from his room to see police officers running toward him with automatic weapons pointed at his face, safety catches off.
"Good as gold mate," Mr Tempero says he responded, before lying face-down in the gravel.
He was kept there, hands bound with plastic ties, until asked to show police the panic room in which Mr Dotcom had taken refuge.
Officers later charged Mr Tempero with possession of the two shotguns found on the property.
The pistol-gripped weapons were not covered by Mr Tempero's firearms licence. The basic charge of possession has since been upgraded by police to possession with criminal intent, meaning Mr Tempero faces up to five years in prison - a potential first blemish on an otherwise clean criminal record.
The high court ruling that the search warrant was unlawful, making the search illegal, will also have repercussions for the charges he faces.
"With everything that has come out, I can't understand why the case hasn't been dropped. It has changed the way I think about the police and what they have done.
"Mainly I think about how the police handled it. That upset me the most. They terrorised a family and staff members. They treated us like criminals."
The FBI view is Mr Dotcom and his co-accused are criminals. The police raid was driven by urgency to locate a potential "Doomsday Device" which would destroy evidence.
The Motion Picture Association of America has a similar position on Mr Dotcom - it has called him a "career criminal". It is a position which Mr Tempero has refused to accept even after the raid left the household penniless.
"It never occurred to me to walk away. I know this man and I know he didn't lie. The one thing you have in a job like mine, where people put their lives in your hands, is integrity and loyalty.
"Why would someone so focused on his family throw everything away? I also knew how smart he was. He could make money doing anything. He didn't need to do anything illegal."
Mr Tempero - dubbed by one blogger as a PA with a licence to kill - has been present at most of Dotcom's business meetings, including one about the listing of Megaupload on world sharemarkets. "Why would you look at taking a company out to the world if you'd done anything wrong?"
Mr Tempero's employment came at a time when Megaupload's profitability soared. In the background was Mr Dotcom's previous offer of a bounty for Osama bin Laden's head (literally, on a silver platter) and the marriage to Philippines-born Mona Dotcom. The risks of kidnapping in the Philippines meant the security threat was high.
Mr Tempero has protected the rich for 24 years, guarding them and those drawn into their circle. He has watched over David Beckham, Whitney Houston, Michael Jackson, Sting, Celine Dion and Elton John.
In Mr Tempero's job, the intent is to stop security problems before they occur. It means playing tactical chess against an opponent who never shows his pieces until the last minute. "I've been trained to do this job by the very best and a lot of it is mental. If you're not smart, you can't do this job."
If problems can't be avoided, Mr Tempero is the final answer to any question about security.
The skills come from a little-known world expert based outside Dunedin. For decades, Geoff "Tank" Todd has been sought after for "close quarters combat" skills, so desired by special forces soldiers they travel to New Zealand to train with him.
Mr Tempero learned the brutal art of removing physical opposition through sudden violence between work at the Burnside freezing works during the day and bouncing at night.
"Knees, throat, eyes - they are the only parts of your body you can't grow muscle on. If you take a knee out, they can't run after you. If you take an eye out, they can't see you. If you take the throat out, they can't breathe."
He won't talk details but has had call to use his skills - and been injured too. "It is the nature of the job."
The learning turned into a job, with work in the US for the Brunei royal family. From there, he went to Brunei then Alinghi and other roles across the world.
When the call came to work for Mr Dotcom in New Zealand in February 2010, he was back with Alinghi in Spain. Oracle won, his employer lost, and he was free to take another job.
Now he lives just metres away from where the family sleep. Every aspect of their movements and plans goes past him.
He knows where Mr Dotcom is - and vice versa - "every minute of the day".
So far, it has worked. "What I liked about Kim and still do, is he is a family man. He's fun. He has become a friend as well as a client.
Q&A Kim Dotcom
Q: How did Kim Dotcom get into New Zealand?
He applied for residency under the investor category, which requires an investment of $10 million for three years. Residency was granted on November 18, 2010, and he flew here about a month later.
Q: Didn't we know he would be a problem?
Actually, Immigration NZ staff put a lot of effort into making sure he would not be a problem. His Megaupload filesharing business, its profits and his wealth were all investigated and given a clean bill of health. Government officials were also aware the FBI was interested.
Q: Isn't he a criminal?
When applying for residency, Dotcom openly stated he had convictions from his teens and 20s for insider trading and computer hacking. The convictions no longer exist - they were wiped from Germany's system under a similar law to our "clean slate" legislation. Government ministers were told his benefit to NZ outweighed any baggage.
Q: Why is he in trouble?
The FBI says he is an internet pirate who has cost the movie industry hundreds of millions of dollars. Dotcom says he is not. A court hearing in March will decide if he is extradited to face trial in the US.
Q: What is he charged with?
Copyright, money-laundering and racketeering. You can't be extradited for copyright violation and racketeering doesn't exist in New Zealand so money-laundering is among the charges.
Q: Why are New Zealand authorities involved?
We were asked to assist under a mutual assistance agreement we have with the United States and other friendly nations.
Q: So what's the problem?
There has been criticism over the way we have gone about helping. First there was the paramilitary raid, the wrong legal orders, the invalid search warrant, the unlawful search and seizure, the removal of evidence from New Zealand against court instruction and, most recently, illegal spying by our intelligence agencies.
Q: Didn't they get muddled on a complicated law change?
The change to the Immigration Act in 2009 meant "permits" were now called "visas". This was the only thing to change in the Government Communications Security Bureau Act.
Q: What next?
The spies are under police investigation and have a new minder in their office checking their systems. There are a handful of connected court cases working through the courts, right up to the extradition case in March. Calls for an inquiry into the affair have so far been rejected.
