They did not have a net negative capital balance, but they apparently had an insufficient net capital balance. I don't know if that was bad data, or what, but the month before and the month after, they had sufficient net capital. http://www.cftc.gov/ucm/groups/public/@financialdataforfcms/documents/file/fcmdata0711.pdf
To be honest, nowadays, that's an afterthought since I've become more concerned with the solvency of these firms. Obviously, I should have acted on it, in hindsight, but with the total lack of transparency and how things are "PR'ed" until the last minute demise, I find it hard to play.
Well considering their leverage, whatever the marks might have been on the date of reporting could have led to alot of fluctuation. It would be helpful if a guy who knew the in's and out's of the accounting chimed in. You have to remember that there was alot of noise about a bond offering within a few weeks of that data coming out. If I remember correctly, there was also the strange kicker about Corzine leaving (for presumably the Treasury post) and the interest rate adjustments.
the ironic Corzine clause http://online.wsj.com/article/SB10001424053111903341404576484211245963554.html
You can read the shareholder letters where he outlines his opinion and position to go long Euro debt because he has the expertise from Goldman and politics. No real reason for him to do time but civil suits are in order.