The basic format of the film was to try and skewer various individuals in interviews. The smart folks declined to be interviewed, but some economists did agree and presumably thought that they were being interviewed for their expertise on the issue. In fact they were being pilloried. Case in point: Glenn Hubbard (Dean of Columbia Business School).
Overall - probably worth watching if you are interested in the topic, but don't treat it like a definitive explanation. A recent article in the Washington Post sums up the movie perfectly.
It was an excellent documentary for people who don’t want to understand the financial crisis but want to believe they would’ve seen it coming.