Nice, but it's fairly easy for NZ to not recognize software patents categorically, as they're not a major export for them. As much as I'd like the U.S. to follow suit, we're a much bigger exporter of patented software tech, and that's going to carry a lot of weight with policymakers. The situation is slightly better in the UK and EU, but actual enforcement is key.
The recent ruling The U.S. Court of Appeals for the Federal Circuit handed down for the CLS Bank v. Alice case shows just how much of a cluster**** this issue is here (i.e., even they can't agree on what's patentable), but has helped set the stage for a reasonable decision by the Supreme Court on the issue. We shall see...
But back to the topic, inducing someone to infringe a patent that is valid in the U.S. by importing (i.e., downloading) your product in the U.S. is itself infringement. So, it's still entirely possible for NZ companies to face civil penalties. IIRC, NZ civil law allows NZ courts to enforce such judgements if it doesn't relate to taxes. And if you're using a payment system based in the U.S., well they can get you there too. Not that I necessarily agree with any of this, but NZ companies will most likely still have to license such tech (especially if they own U.S. assets) if they want to sell their stuff to U.S. citizens, at least.