You see, I find the whole story fishy.
I mean, think about it...
Why would members of the development team entrust sensitive information to a random stranger?
Especially considering that both Nintendo and Sakurai are both very strict about leaks.
The best example for just how strict Nintendo is... is "Splatoon".
Or rather, the game that was originally supposed to happen in its place.
Long story short:
Nintendo approached a development team (High Voltage Games) with experience in shooting games, to make a family friendly shooting game.
The game's concept was robots shooting water guns to neutralize each other, if you must know.
Anyways, rough development cycle aside, one unknown member of the development team, leaked information out of spite.
Nintendo issued an ultimatum, to find out who the leaker was and stop further leaks.
But the development team was unable to do so and so Nintendo straight up killed the project and cut ties with the developer.
Eventually Nintendo had one of their own development teams do the development of a family friendly shooter instead.
And so Splatoon was born.
But yeah, this should give you a good idea just how strict Nintendo is here.
Given that, what kind of dev in their right mind would take such a risk? Leaking information to strangers?
What could they possibly hope to get out of it?
It's just not believable to me.