My theory is that Mark Karpeles himself leaked this documents and is pretending his website and reddit got hacked, to strengthen his argument that the coins got hacked.
There isn't really any way to prove if he did or not.
Probably partially true...
I think he is on a Government gag order, if he talks directly he will go to prison for long time, and in this way he can give the info to the world.
They said on multiple occasion that there was an investigation that they could not talk about and at the beginning they also said they still have the BTC, but for a technicality, of which they also could not explain in details) could not be accessed. And about that part somewhere else few days ago some big wallet start moving BTC around.
The BTC are there and somewhere in the world are also the Keys.
It was claimed on irc by the original 'spokesperson' for the hacker group that they'd had access to mtgox servers for a long time. Taking that into consideration, it would not be strange if they had access to login credentials for Mark to various services. Judging from the level of security he's been running, he might as well have stored all passwords in a text file..