Earlier quoted context omitted.
Likewise, just because they caused the financial collapse doesn't mean they broke the law.
CDO (Collateralized Debt Obligation) origination fraud is a crime. The GFC was not caused by law abiding activities. It was fraud, plain and simple. https://www.justice.gov/opa/pr/bank-america-pay-1665-billion... As part of the RMBS Working Group, the U.S. Attorney’s Office for the District of New Jersey conducted a FIRREA investigation into misrepresentations made by Merrill Lynch to investors in 72 RMBS throughout…
What you're describing in the paragraph above is even one step removed from the sandwiches. Knowing that "loans had material underwriting and compliance defects" doesn't prove that Merrill Lynch lied when it said "the borrowers ... were likely and able to repay their debts." It might lead to an inference to that effect, but it's not indisputable proof. Likewise, the fact that it "rarely reviewed the unsampled loans to ensure that the defects observed in the samples were not present throughout the remainder of the pools" might lead to an inference of negligence, but is not indisputable proof of fraud.
Everything described in that paragraph is classic civil fraud and negligence, not criminal fraud.