Later this day, a group of hackers gained access to MtGox servers and executed fake trades that the world could see, driving the nominal price of bitcoin near $0. Mark was frantic. He quickly regained control of the servers and learned the dark truth: the million bitcoins that had recently flooded in earlier that month were gone. Mark admitted publically to the hack, rewound the false trades, but kept the truth of the missing coins a secret.
I remember a thread after the june/2011 hack from an user that bought ~200k coins at $0.01, and, theoretically, it saved mtgox from losing it all because he was able to buy before the thief had a chance to withdraw, and that drove the price back to $0.30, and the thief only got ~2600 coins. (Edit: because of the U$ 1000,00 daily limit at the time). That was the "oficial" story.
What's left, at least for me, is to check for any confirmation of a $1000k steal on that day. We are looking for $1000k coins which mostly entered Gox during the weeks before and then were all spent more or less at once. The thief would have had to do the latter in order to prevent Gox from spending them first using a backup of the wallet, after the theft had been detected.
+1