New Zealand is still a constitutional monarchy, with Queen Elizabeth II as nominal head of state, and its law is still largely based on the old English Common Law, dating to before the Norman Conquest in 1066. While in recent years, NZ has looked to the USA, Canada and Australia in new-law modelling, Common Law and English jurisprudence still maintains strong persuasion in the courts there. Now, Common Law is based on perceived common sense, ( cf. Lord Denning.) and to expect any court to uphold a tort (grievance) attested by a plaintif on unreasonable grounds, like "He changed a receptacle, therefore it's all his fault the building caught fire.", for example, would almost certainly fail, given a competent lawyer and given lack of proof of direct responsibility. To get any action to succeed, Mike, you must have some proof of culpability and I think you're being a bit pessimistic as to the fairness of New Zealand's legal system.
Having said all that of course, we poor English ouselves no longer have the protection afforded by the old Anglo-Saxon codes, and are now at the mercy of stupid European lawmakers with the facile 'Bill of Human Rights', which rides roughshod over a 1000 years of hard won freedoms!
Alan