Under international law, that is the day New Zealand became an independent sovereign state on an equal footing with the rest of the world, but what the colonial government at the time did not realise was the legal implications of that. If you look at Hong Kong as an example, at one minute to midnight British law still applied, but at one minute past midnight Chinese law applied. It is what constitutional lawyers call 'a break in legal continuity' and it is a requirement of sovereignty transfers. There was no switch over. All the old laws and political machinery continued.
Constitutional experts say that failure has huge implications.
Legally, all laws in existence in New Zealand up to that point ceased to exist, because they were old colonial laws. That means the Treaty of Waitangi also ceased to have any legal standing as well. But instead, the bureaucrats and the Government presumed that they could remain in power without any legal changes. As a result, we've had an illegal government since 1920 and all laws passed since then are invalid. Australian constitutional experts quoted in the magazine say the problem is mirrored in Australia and Canada.