"He'll know what the DOJ is about very soon."
Well, they probably have already heard where the phony medical document Pitt tried to peddle on CU during the great internet fundraising hoax, otherwise know on DU as The Andy Stephenson Situation, came from.
They'll probably just ask Pitt a few questions to confirm the credibility of their source.
In all seriousness, this essay could be prep for a future arrest he's expecting over that schoolgirl issue or other malfeasance. He can muddy the waters by planting the idea in their heads ahead of time that he's beeing taken out by Bushco.
If I had his fat ego and his super-credulous audience, it's what I would do if I expected to be weearing an orange jumpsuit.