If TVNZ pays that means the taxpayers pay
Not legally - if TVNZ pays then a company in which the Crown happens to own shares pays. And they are a commercial operation, so presumably the Board thinks it's to the company's commercial advantage to do so, otherwise they wouldn't do it.
Spark and TVNZ have partnered before when Lightbox Sport had EPL and Golf rights.
Lots of ways to slice-and-dice rugby World Cup rights.
All games involving the All Blacks could be free-to-air on TVNZ, while Lightbox has every single game, plus ondemand and mobile app options.
Depending on the pricing, it could be simultaneously broadcast on Lightbox and TVNZ. The Lightbox stream could be uninterrupted while the TVNZ broadcast contained the usual saturation-bombing of ads and promos. At the right price, many people may consider that it's worth paying Lightbox in order to avoid that agonising viewing experience.
1. It depends if there is a commercial advantage, ie. a profit to be made.
2. Its a big deal, I can't see opportunities for ads being passed up