[ by Melanie Gretchen ] Rajat Gupta's lawyer faced Goldman Sachs CEO Lloyd Blankfein over the course of his client's trial.  Testifying for the prosecution at the trial of Rajat Gupta, the former Goldman director accused of insider trading, Mr. Blankfein has essentially relinquished his duties as chief executive [CI Note: he couldn't even check his BlackBerry!], to discuss Goldman’s inner workings, from the contents of board meetings to his relationship with his officers, in Federal District Court in Manhattan before Judge Jed Rakoff. The Prosecution's Case. On Friday, Mr. Blankfein took center stage as defense lawyer Gary Naftalis tried to show that some of the information Mr. Gupta is accused of leaking to hedge fund manager Raj Rajaratnam was known by the market and thus not "material nonpublic information" under the insider trading laws.  Toward this end, Mr. Naftalis showed Mr. Blankfein 2 reports from analysts who followed Goldman during the 2008 financial crisis. Reports. Written by analysts at Merrill Lynch and Oppenheimer, the reports raise the prospect of Goldman buying a retail bank.  Both reports came after meetings with top Goldman officials.  "GS Bank & Trust?" said one report.  "Don’t rule it out." Azam Ahmed and Peter Lattman of Dealbook have attributed the defense presenting the reports to the jury as a means of minimizing damage from the only phone conversation between the 2 recorded by an FBI wiretap.  During that call, in July 2008, Mr. Gupta tells Rajaratnam that Goldman’s board is considering buying a bank.  [CI Note: Were those reports in fact public, or the product of a leak?] The Voicemail. Before resting their case at week's end on Friday, prosecutors played several secretly recorded short voice mail messages left by Mr. Gupta on Mr. Rajaratnam’s cellphone.  During one on 10/10/08, during the financial crisis, Mr. Gupta says: "Hey Raj, Rajat here.  Just calling to catch up.  I know it must be an awful and busy week.  I hope you are holding up well.  Uh, and I’ll try to give you a call over the weekend just to catch up.  All the best to you, talk to you soon.  Bye bye." Mr. Gupta’s lawyers have said that by October 2008, their client had lost his entire $10 million in a Galleon fund, after which he had a falling-out with Mr. Rajaratnam and thus had no interest in passing along insider tips.  To this end, the defense played a videotaped deposition of Ajit Jain, chief insurance head of Berkshire Hathaway.  Mr. Jain, a friend of Mr. Gupta, said that during a lunch in January 2009 at an Italian restaurant in Stamford, Conn., Mr. Gupta told him about the bad blood. "He told me that he had $10 million invested and he had been gypped, swindled and cheated by Raj and had lost his $10 million." The prosecution sought to debunk that theory with the friendly tone of the voice mail message, after which prosecutor Reed Brodsky rested the government’s case.  [CI Note: Will it be enough?  Stay tuned.]