I agree, after reading it a couple times I think the leak is fake.. it just seems so far fetched. It's weird that several parts of it have been confirmed independently though, something just isn't adding up.
"A leak in out hot wallet" causing coins to be lost from their "cold wallet". If that truly happened, then they have the worse security practices ever...
Well a cold wallet isn't really a cold wallet if it can leak coins through a hot wallet anyway.
The number itself is very far fetched indeed. A theft of this magnitude would not go unnoticed for very long, not to mention if it were real a single person or entity would effectively have the power to dump every exchange's order book to pretty much zero. I think the problems at Gox are still much more fiat liquidity issues coupled with technical problems Mark has no clue how to solve.
Oh, and the entire "internal" document refers to Gox in the 3rd person as if commenting on the situation from the outside.