c100driver: It is one of the subtle points in the NZ regs that works very well.
For example, Rather than "this is how you must comply" the New Zealand rules state that the operator has to show that they meet the requirements of a certain rule. To put it another way, the rule says you must comply with this requirement but you demonstrate how you will comply.
The CAA can publish an Advisory Circular (AC) on how you can meet the requirement. However if you can demonstrate to the director that you can use a different methodology to achieve the same intent of the rule then it is accepted. The AC is not law but is one way you can comply.
It is a collaboration of the CAA and the Operator to achieve the compliance required in the rules rather a dictate from the director how you fly your aircraft.
+1
However I suspect some aviators in the West Island are so used to very prescriptive rules they wouldn't understand.
Our CAA do some daft things but the NZCAA rules do work pretty well.