Yeah. Pretty much everyone agrees on the first bit, that somehow Mt Gox got into trouble, and tried to get out of it by gambling with the customers' money like a bank (but uninsured!). The question is what that trouble was. It does not go back to when bitcoin was worth pennies, that I'm pretty confident of. I'm also pretty confident that it wasn't the transaction malleability bug itself - at worst, that could have drained the
However, the transaction malleability bug might have been the trigger - or rather, the bank run it provoked was the trigger. As people were trying to withdraw bitcoin, Gox tried to dip into their long-term storage (cold wallet) - and they made an unpleasant discovery.
What? That some of the cold wallets were empty, drained by an unfaithful employee? That they'd lost the passwords to some cold wallets? I don't know. Anyway, they briefly tried some desperate things with the money they had, in order to fix the problem before anyone knew. It failed. Then they went to other exchanges for a "bailout", trying to buy more time to fix the issue. Then the other exchanges demanded they come clean and reported them to the authorities.