Hunter was the bag man. He was in charge of laundering the money, and he was in charge of managing communications to mine for blackmail footage to use as leverage.

That's how the game is played, if you're caught up in this, basically you have to document all your corrupt activities and disclose them to the rest of the cabal, so they can all have a gun to each other's heads at all times.

This is the only reason I can think of why he'd so obsessively catalog all of this shit.