I really wish there was a simulation where we can hold certain events like "mortgage underwriting standards" and "1% federal funds rate" and isolate it. I have a feeling he has good points but is still not giving enough weight to the low Fed Funds rates from 2001 to 2005.
Of course he isn't giving enough blame to low interest rates? Why would he? He knows low interest rates largely caused the bubble (along with some other less important factors), but he does not want to damage his buddy Greenspan's reputation.