UPDATE:
Goldman CEO, Lloyd Blankfein says that ACA bought 90% of Abacus and worked with Paulson in creating the product. He also said that it was assumed that all parties involved should have known each others’ interest even if it wasn’t explicitly disclosed.
However, it is still likely (the details have yet to fully emerge) that Paulson selected ACA for his own interests (they were the most gullible?). It is also possible that ACA, at the time of the creation of Abacus, might have even believed that Paulson intended to take the other 10% of the product rather than subsequently short it, as the SEC complaint alleges.
Still, even if ACA knew of Paulson’s interest, IKG, the actual buyer of the remaining 10% of the deal, was not formally informed via the offering documents that Paulson was allowed to influence the creation of Abacus to its buyers’ detriment and to his own benefit. And I still believe that this is hardly immaterial.