Yes the hacker was a guy called Hufflepuff and at first everybody was amazed at his luck and then it took them a while to realise that the guy actually cheated.
If you got some spare time, there is a summary in this thread:
https://bitcointalk.org/index.php?topic=843892.0The videos are still working on Youtube and looking at the videos it looks like legit bets actually. Pretty crazy with the amount of BTC that the guy ran off with. Was a huge blow to the site and the gambling industry back then.
The bets looked legit because Hufflepuff figured out to get the server side seed and that means he could understand what value will come next before rolling and primedice took some time to figure out the security loop hole, it looked like an inside job by the way the hacker figured how to get the combination of server client seed and nonce, but Stunna later explained that he did not run away with all the coins he won through that loop hole but he ran away with a huge amount either way.
True, it does not matter anymore, the deed is done. What should really be the focus now is the prevention of these future hacks.