Similar to Abacus, a Bear CDO deal that went sour came with some incriminating emails from the underwriters:
http://www.theatlantic.com/business/archive/2011/0...
In the case of Abacus and SACO, there seems to be a pretty clear trail of wrong-doing on the part of the underwriting bank. However, plenty of other bad deals were underwritten by bankers who either knew (or should have known) what they were doing. This one takes it a step further by alledging additional fraud in the actual execution of the deal.