richard bowen: there are things that obviously went on in this crisis, and decisions that were made, le need to be accountable for. >> kroft: why do you think nothing's been done? >> bowen: i don't know. >> kroft: until 2008, richard bowen was a senior vice president and chief underwriter in the consumer lending division of citigroup. he was responsible for evaluating the quality of thousands of mortgages that citigroup was buying from countrywide and other mortgage lenders, many of which were bundled into mortgage-backed securities and sold to investors around the world. bowen's job was to make sure that these mortgages met citigroup's own standards-- no missing paperwork, no signs of fraud, no unqualified borrowers. but in 2006, he discovered that 60% of the mortgages he evaluated were defective. were you surprised at the 60% figure? >> bowen: yes. i was absolutely blown away. this... this cannot be happening, but it was. >> kroft: and you thought that it was important that the people above you in management knew this? >> bowen: yes, i did. i... >> kroft: you told people. >> bowen: