I can say 90% that this is what happened, he lost the private key, but he thinks that he can recover it, he reached for help, he told the Big guys about the problem, they were shocked and didn't want to help him and went out in 24 hour to tell us that Mtgox is insolvent instead of helping him recover customer funds, it was interesting how they just made a statement in 24 hours without any explanation to just tell everyone forgot your funds...