There's an old saying: Academic economists have successfully predicted nine of the last five major recessions. That is: One possible answer to the question in the title is: "Because actually the available information didn't make it clear what would happen and when; you thought it did, but actually you just got lucky." Whether that's actually the case here is of course difficult to tell. On the one hand, hindsight bia…
I have to agree with the idea that he just got lucky. If he was really so sure of his assessment back then then why didn't he short sell a bucket load of these mortgage backed securities?
This was really a great trade because his losses were capped at around 5% a year while his upside was huge, imagine a 6:1 payout.