What he did should not be legal here. But he may have been clever enough to be at least in the grey area of the law. At least the law in NZ. From a strictly moral standpoint, he was ripping off the copyright holders no doubt and should not have been able to get away with it.

The problem is he is getting extradited on these parts of the treaty:

Receiving and transporting any money, valuable securities, or other property knowing the same to have been unlawfully obtained.

…

Obtaining property, money, or valuable securities by false pretenses or by conspiracy to defraud the public or any person by deceit or falsehood or other fraudulent means, whether such deceit or falsehood or any fraudulent means would or would not amount to a false pretense.

I'm not sure you can argue that he did that, and if that is the case, you have to ask what is going on here?

Of course, there is much to this that I don't know, but still it's a bit fishy.