RCD & Test and Tag
My take, FWIW, Electrical Appliance Safety is a tripod, supplying appliances via a "regularly tested RCD" type A is one leg, Competent test & tag of appliances should confirm that tagged appliances comply with NZ Electrical Safety requirements and are "safe" to use at that point is the second leg, regular "documented" user checks are the third leg.
The legal obligation to do "something" is created by Regulation 15 of the Electrical (Safety) Regulations:
15 Using works, installations, fittings, appliances, and associated equipment
(1) A person who owns or operates works, installations, fittings, or appliances must not use, and must
not allow any other person to use, the works, installations, fittings, or appliances if the works,
installations, fittings, or appliances are electrically unsafe. .
Regulation 26 describes some ways that this obligation can be discharged by the person responsible for an electrical installation, or hired or rental equipment,
26 When fittings and appliances in use deemed to be electrically safe
(1)This regulation applies to a fitting or appliance, other than an electrical medical device, that is in
use, or available for use,—
(a) by an employee or contractor of the owner of the fitting or appliance; or
(b) by a hirer or lessee under a hire or lease agreement with the owner of the fitting or appliance; or
(c) by the occupier of premises that are rented or leased from the owner of the fitting or appliance.
I would suggest reading the whole of Reg 26, and not just extracting the portions of it that suit your position.