Expat kiwi here. Unless something has changed in the last 5 years - security personal in New Zealand generally don't carry firearms and I don't believe there is a legal justification for lethal force. We don't have anything like the "Castle Law" found in some US States and gun owners rarely use firearms defensively. Also, if people dressed in black and armed with M4's are knocking on your door you can safely assume it's the Police in NZ.

It's hard to understand why they would raid his house like this.