Knack 2 FREE on New Zealand PSN

Why does this keep happening with PSN specifically? I remember Xbox having some sort of similar thing, but it eventually stopped due to some glitch with games not sold in certain areas and thus having default price of zero being fixed, right?
I see $39.99.

EDIT: I logged out of my us account and clicked on the url again. it shows as free. added to basket. created a fake new zealand account with a real email, verified it and was able to order without adding a credit card.

thanks OP!