There is specific wording in the copyright amendment act -

In sections 226A to 226E, unless the context otherwise requires,—

TPM or technological protection measure—

means any process, treatment, mechanism, device, or system that in the normal course of its operation prevents or inhibits the infringement of copyright in a TPM work; but

for the avoidance of doubt, does not include a process, treatment, mechanism, device, or system to the extent that, in the normal course of operation, it only controls any access to a work for non-infringing purposes (for example, it does not include a process, treatment, mechanism, device, or system to the extent that it controls geographic market segmentation by preventing the playback in New Zealand of a non-infringing copy of a work)

TPM circumvention device means a device or means that—

is primarily designed, produced, or adapted for the purpose of enabling or facilitating the circumvention of a technological protection measure; and

has only limited commercially significant application except for its use in circumventing a technological protection measure

TPM work means a copyright work that is protected by a technological protection measure.

Section 226: substituted, on 31 October 2008, by section 90 of the Copyright (New Technologies) Amendment Act 2008 (2008 No 27).

My interpretation of that means that defeating geoblocks is perfectly legal if what you are watching allows you to watch it in your area. I guess this is the "grey" area, in that Netflix etc are only able to give copyright in each market, so by circumventing geoblocks, you are watching illegal material (?)

This is ofcourse only a slice of the legislation but seems to apply. There are other provisions whereby the person parallel importing the content has to have reasonable grounds to assume (or prove) that the works do not infringe on the rights of the copyright holders. Again, with Netflix, its hard to argue that you don't know that they aren't allowed to sell viewing rights in different markets.