Section 17 of HSWA defines a PCBU and also who is not. Given the contestants live onsite, they may be defined as being the occupants. Hence HSWA does not apply as the workplace is not their place of work. Others who do not reside there may be determined as workers so HSWA applies. — KeithH

Simply living on site doesn't mean you're not a PCBU. I work from home, but am definitely a PCBU.
They do not own these properties, and are doing this for profit, so it's hard to see how individual contestants would not be considered a PCBU in this case.

The limitation on occupants is to prevent homeowners or tenants from being liable if a builder they engage to do work hurts themselves, due to something the homeowner likely had no knowledge/control over.

This sort of approach will make little to no difference to health and wellbeing.

"Health is related to unseen and unspoken energies.
The spiritual essence of a person is their life force. This determines us as individuals and as a collective, who and what we are, where we have come from and where we are going.
A traditional Māori analysis of physical manifestations of illness will focus on the wairua or spirit, to determine whether damage here could be a contributing factor."

Starting to blame illness on 'spirits' is taking us backwards, not forwards with regards to our wellbeing. It also fails to acknowledge the significant portion of our community that have no spiritual outlook on life.

No approach or framework for wellbeing that I have seen has ever acknowledged that we are all individuals, with different goals, beliefs and situations. That is what we need, something that allows flexibility to treat people as individuals and involves them, not blaming 'unspoken energies'

The risk matrix is simply one way of communicating where risks are perceived. It is a communication tool, and in no way should it ever to be seen as an exact calculation of a risk. After all, every hazard has multiple outcomes. It may have minor consequences most of the time, but a major consequence very rarely. So a risk actually lives in an area within the matrix, not a single point.
My opinion is that we, as humans are horribly bad at understanding, and acknowledging extremely high consequence, extremely low likelihood risks (think Covid Pandemic). This is the root of the failure to adequately deal with these risks, not a communications tool.

Do I phone up my insurance underwriter and ask his opinion or can someone in the know advise accordingly. — Greg Sutton

They are likely to give you better guidance on exactly what you require, and are likely ot be more stringent than building regs, etc.

May block...
There are plenty of other emergency exits, for whatever the emergency is.

The trolleys at the checkouts aren't only there to show that the checkout is closed, they are there specifically to prevent people moving out of the store without going past an employee, thus deterring theft. I think you'd also find that liquor licensing authorities would have something to say if minors were able to pick up wine or beer and just walk out.

Unintended consequences....

Under the Fire and Emergency New Zealand (Fire Safety, Evacuation Procedures, and Evacuation Schemes) Regulations 2018 FENZ can require building owners and/or their tenants to supply and maintain portable fire fighting equipment ( see clauses 14 & 15) — Steve H

And a lot of it is also driven by the building's insurance company/sprinkler requirements, etc.

I've got a client who does the same - inside his workshop, no permit. But in another workshop, where hot work is not normally carried out, he does go through the permit, mainly to ensure that the client is aware of any risks.

He wasn't an immediate risk to anyone in the next aisle.

I'll defer to the professionals on evacuation, I'm no subject matter expert.

Those displays aren't 'unanticipated', they're all planned out. IMO, adding an additional layer of complexity, and unnecessary cost isn't going to make any difference. Supermarkets are low-density as far as occupation goes; even in a full supermarket, they don't come anywhere near maximum occupancy densities allowed for in evacuation schemes.
In the Dunedin case, was there a need to evacuate the building as quickly as possible?

Supermarkets evacuation schemes are well-defined and planned, taking into account the fact that most checkouts will not be available. There are professionals whose job it is to develop evacuation schemes. IMO, this is a perception that does not accurately reflect the real risk.

And that is all that HHFE is for. It is NOT to extinguish the fire, but to keep it contained/away from people to get people out of the way.

Just to throw another spanner in these works: What do the building's and company's insurers have to say on the matter? With fire protection, it is often these requirements that are a driving factor.

To be honest, I wouldn't even bother to push back.
If you've passed the audit, then I'd ignore the request, or at most respond with "thank-you for the suggestion, we have investigated it and found that it is not suitable for our requirements."
As Garth has said, a cross-reference is useful and is something I include in all of my manuals, particularly when various requirements are met within one manual.

Our school doesn't hold them in general, but those students who need them have them either on their person, or held at the office for them. Similar to Rebecca, we have an info sheet for each student, with photo and treatment information
I'd be cautious about the school holding them available for use, as to my knowledge they are prescription, and teachers aren't qualified to make decisions regarding administration.

I would question the ability of a private investigator or lawyer to conduct a safety investigation as the outcomes and methodology is different.

You want someone to not cooperate with a safety investigation? Get a lawyer involved.

Making him take leave? Can't see how the company can force him to, unless they give the required notice. If the company deems there to be a fatigue risk, then it needs to be given, as paid time off.

Do they realise that next time they ask any employee to work overtime, the answer will be 'NO!'

There is now a move away from prescription-based FRMS, and each operator/operation type is now starting to have to come up with its own scheme for approval for their own operational profile. i.e. the fatigue profile is different for a pilot flying long-haul international when compared to one who is flying regional flights.

As Andrew said, its very job and person specific.
The civil aviation advisory circular is here: https://www.aviation.govt.nz/rules/advisory-circulars/show/AC119-2
There are different levels, depending on crew, operation type, etc. Some operations don't have rules regarding flight and duty time, as the risk resulting from a fatigue crew is low enough that legislation isn't considered appropriate (flight training is one of them, as you generally have a second pilot on board.

This is one area where you can readily get beyond 'reasonably practicable' with your risk mitigation strategies. e.g. it is not financially tolerable for individual helicopter operators to get an individualized fatigue management procedure. It has been left to the industry body to do this so that the cost is spread.

I look after safety reports for a primary school, and we actually look for certain types of reports.
trips/grazes, bumps, minor sprains, etc are all a sign that the children are outside, active, and learning physical awareness.
A bit counter-intuitive, but not all injuries are bad, especially in a learning environment. Sometimes when people are physically pushing themselves, injuries are unavoidable.

Yeah, and often these are given at a building that is 90% of the time occupied by member of the public who don't receive (or need) this info.
All public occupied building have evac schemes developed at the building design stage with the assumption of occupants not having this info. So, what is being achieved with the 'usual H&S stuff'?