The account was locked as a security precaution. He probably won't get it unlocked unless he signs from an address that he controls. I would ask him the reason for leaving the development team so abruptly and not touching his BTC. Afterall, he could have just sold majority of them if he have control to it.
After the forum got hacked Theymos advised us all to change our passwords, especially if they were short or a common phrase. Satoshi probably had a strong password so it's not probable that his account was hacked, but even the best programmers aren't infallible. Sometimes they use a weak password to save time when logging in. I suppose it's always faintly possible his account was hacked so Theymos would have to ask him to sign a message given the importance of his account.