So does that mean there is no actual technological proof the words are genuine?
Dude you're tossing around concepts like "proof", "facts", "evidence" with some anonymous dude on a forum who refuses to substantiate any claim he makes.
The chain of custody is hopelessly compromised for all the material taken from Slater. There's no way of determining whether the material has been altered. It's passed through an unknown number of systems. There's nothing released so far that would indicate the hacker(s) are NZers, and not a foreign agency.
The material is being drip test feed in a way that will encourage people to stop taking care about what they download. Just one PDF containing an exploit could compromise a huge number of high value targets.