Luck?
He has broken no laws in New Zealand... the NZ Police and the GCSB overreached with their spying and the execution of the search warrant (the warrant was found to be not legal). The US tried to get him extradited, so the Judge asked to see some of the evidence... (presumption of innocence you know), and the US said 'were the US, we want him, hes guilty', so the Judge said prove it. Seeing as the extradition hearing still hasn't been heard in it's entirety, he's still here in NZ.
You can argue luck all you want, but what matters here is New Zealand law, and the opinion of the Judge (btw Kim Dot Com is a New Zealand resident, so is subject to all the rights that kiwi's have)