I don't know anything about NZ police, but if they are anything like police in the US they are blindly loyal to each other and not to the people whom they serve.
They will use the excuse that they are just following orders, and give no thought to the fact that after WWII that was the excuse so many SS officers gave. It did not matter then, and shouldn't matter now. They need to follow their conscience if they know what they're enforcing is wrong.
The most shameful displays of police I've seen since Covid started were in Australia and Canada.