Twice in e-mails to his father, Sieracki said, "I can lose my net worth or go to jail for things I don't even know."
Asked about the statements during a deposition, Sieracki said: "That was an inside joke between me and my dad. I had heard Angelo make that statement, and I didn't know about the legal veracity of that since I am not an attorney, but I found that concept amusing."
Columbia Law School securities law expert John Coffee said the e-mails and notes, while evocative of the atmosphere at Countrywide, "aren't a smoking gun."
Coffee added, though, that the SEC might find it "useful to show Mozilo was excluding others" from important meetings. "Excluding others may suggest you have something to hide," he said.
Under skeptical questioning by Judge Walter at a hearing last week, Sieracki attorney Shirli Weiss said the remarks were "tongue in cheek " and reflected "some black humor."
Weiss, along with lawyers for Mozilo and Sambol, declined to discuss the filings.
John M. McCoy III, the lead SEC attorney in the case, said the agency wouldn't call attention to the numerous other investigations and lawsuits targeting Countrywide as part of its main case but might introduce such evidence as rebuttal testimony.
The SEC, for instance, said it might want to use a 2007 letter to Mozilo from Stanley M. Crisp, the head supervisor of large banks at the San Francisco Federal Reserve Bank.
The letter to Mozilo said regulators already had told Countrywide executives earlier that year that the lender had "a pattern or practice" of charging African Americans and Latinos more than white non-Latinos in similar financial circumstances for 30-year fixed-rate mortgages.
Crisp told Mozilo that an analysis of additional information Countrywide had provided in response to the lending bias accusation "confirmed, and in some cases strengthened, our earlier findings."
Justice Department civil-rights spokeswoman Xochitl Hinojosa said this week that the department had an open investigation into the Fed's finding of lending bias, but she declined to comment further.
The Fed's findings about racial bias and the Justice Department investigation have not been disclosed previously, though allegations of racial discrimination have been made by several states and in private lawsuits filed against Countrywide on behalf of minority borrowers.
Four lawsuits seeking class-action status on behalf of minorities have been consolidated for pretrial proceedings in federal court in Louisville, Ky.
Countrywide disputes that there has been any discrimination against minorities, a Bank of America spokeswoman said.