This is inconsistent with the ~900 BTC dissapearing from dice.ninja into 1 of his PD deposit addresses, in the days before the heist none the less.
Maybe not. If don't know if there is an easy way to transfer funds between PD accounts and/or generate new deposit addresses. It probably doesn't matter much in the grand scheme of things though.
PD rewards you for sticking with the same account (achievements, levels, faucet, etc.) and dice.ninja didn't.
It's not much, but could explain the difference.
Also, AK seemed to have a real war going on with PD. He kept returning there to try to break even, whereas on most of the other sites he didn't seem to have much trouble winning a bunch of coins and stopping. It was like he couldn't bear to leave an account with negative profit. Maybe all his DN accounts had zero or positive profit, so he didn't feel that draw to "get even" there.