Sounds like he's calling the risk ratings "fraud." It would be a tough case to prove, though. There were two convenient mistakes that nobody wanted to stop making. First, the incorrect ratings, which were motivated by a conflict of interest: the folks selling the mortgage-backed securities paid the ratings agencies to rate their securities. Second, the fact that people bought the securities as if the ratings were trustworthy, despite the glaring conflict of interest.
To make a criminal case, you'd have to prove they weren't just stupid. (Sorry, Ivy League grads, that degree is not sufficient evidence by itself.) Somebody would have to find a paper trail that proved the criminals' state of mind, like an email saying, "Hey Joe, I just finished rating the latest mortgage-backed CDOs. The computer gave them all AA (LOL!) I wonder how long we can get away with using this stupid formula to overrate CDOs. Our customers love it so much, and we are getting mega rich. The people who buy these things are suckers, but they're probably getting rich selling them to somebody else LOL. Everybody gets rich except stupid grandma when her pension fund goes broke LMFAO"