Ann: Market Update CEO Announcement and General Law Review, page-59

If we say a black swan is something that is not predictable to mainstream financial analysts then yes the GFC was unpredictable.
They aren't entirely blind, they can see about 3 inches in front of their face.
If your economic modelling includes the effects of resource costs and speculation then financial crises are predictable and in fact the inevitable consequence of current actions.
That's only the "backwater" economists who have real models.
The shorters knew that subprime lending was a massive fraud and they bet hundreds of millions against it. They knew the GFC would happen as a consequence of the fraudulent lending.
If a shorter goes after a good company they get killed, if they want to euthanase a bad company it is to stop the rot.
They have to be a lot smarter than longs but because it's an area few inhabit I think the short side of the market is extremely inefficient so the opportunities are great.
Just look at how the holders of SGH reacted when it was a hot stock. There was very little risk being short if you knew about nonesense at Quindell.
On the other hand the risk of being long SGH was pretty high.
You can't make categorical statements, short or long is fine if you do your homework and are conservatively financed.