Heres another guy that tried to warn them, and DID heavily SHORT everything going into this debacle.
It's a long article, but interesting.
One thing I found interesting His purchase of CDOs allowed the brokers to create MORE CDOs which he bought which allowed them to .....
This to him proved it was a house of cards, they were running out of borrowers to create the CDOs that made the income.
http://www.portfolio.com/news-markets/national-news/portfolio/2008/11/11/The-End-of-Wall-Streets-Boom?print=true