“This is so significant that it could have an impact on future deals,” the analyst wrote, according to the complaint. “There’s no way we can get back on this one, but we need to address this now in preparation for future deals.”

Volume, Standards

In 2007, one CDO analyst wrote to a former co-worker: “Does company care about deal volume or sound credit standards?”

E-mails and text messages can give prosecutors insight into the “unvarnished perspective” of company insiders and help them win trials because they’re easier for jurors to understand than more formal documents, said Robert Mintz, a partner at McCarter & English.

“They tend to give jurors a flavor for the general atmosphere inside a company, and that in connection with other documents can often be quite damning,” said Mintz, a former federal prosecutor in New Jersey.

S&P said in a statement that the government’s lawsuit is “meritless” and that at all times the company’s ratings “reflected our current best judgments” about mortgage securities and CDOs.

“Unfortunately, S&P, like everyone else, did not predict the speed and severity of the coming crisis and how credit quality would ultimately be affected,” the company said.

‘Cherry-Picked’

The reference to a deal “structured by cows” had “nothing to do with RMBS or CDO ratings or any S&P model,” it said, contradicting the complaint. RMBS stands for residential mortgage-backed securities.

“The e-mail excerpts cherry-picked by DOJ have been taken out of context, are contradicted by other evidence, and do not reflect our culture, integrity or how we do business,” it said.