I definitely think the next comment has to be true (that gox was net short) if the willy bot scenario is true
https://www.reddit.com/r/Bitcoin/comments/3fe92x/im_ashley_barr_aka_adam_turner_the_first_mtgox/ctor4f3It's basically this, which was very insightfully written at the time:
Peter Rs Theory on the Collapse of Mt. Gox
TL/DR: A young man had a secret. To keep it hidden, he kept digging until the hole was a billion dollars deep. This is a speculative tale of a great bitcoin theft from MtGox in 2011 and the efforts that this man undertook to fix it. The tale explains the bitcoin bear market of 2011, the explosive rally of 2013, delayed fiat withdrawals, malled transactions, and a bot named Willy.