Missing the point
The developer was already giving the app away free on iTunes, they just wanted to add a charge for the app that would be then sent to a charity.
Plus I'm pretty certain that there would be rules within NZ to deal with people who claim to be collecting money for charities and don't hand it over (Although non it to deal with charities who then waste or use said funds for other means such as happened in the Gulf after the hurricanes there)
The best solution would be to have a link from within iTunes to a webpage that links directly to the funds webpage so the money would go direct to the fund , but is credit as coming from the developers efforts, since the app is free then no harm done.
To people saying there are other ways to donate, a lot of people around the world probably wouldn't know there was a Quake in NZ (it took me three days, since I rarely watch news on TV), so this is one of the ways the message would get out, and congrats to the Dev;s for trying.
putting my coat on because it actually portrays what apple does to its vendors and customers (i.e pick pockets)