I had a similar experience yesterday.

A family bereavement resulted in last minute changes to a booked smart saver. I went through Air NZ's compassionate process which resulted in the $50 change fee being waived, and a much lower fare difference (the compassionate fare is V class, the lowest flexi fare, when only B was available otherwise). However I did need to pay the $30 service fee.

Now I'm not complaining at all - I think it is fantastic that Air NZ have the compassionate policy and was very grateful for the assistance. It just struck me as odd to charge a service fee to access a compassionate policy. I last had to do this ten years ago, and at that stage the policy was to change the flight as required, with no fees and no fare difference either.