I totally agree airlines will be the problem. Their financial incentive is to cover their asses unless you have a slam dunk case in suing it.

I will go further than docbert: get the advice *leaving* for NZ before 1 Oct arriving 2 Oct is ETA free, in writing from immigration.govt.nz email, with the officer's phone number on it so airline can confirm. Anything less, cough up for the ETA - not worth the grief.