 In May, Lehman's CFO Erin Callan held a private teleconference with Einhorn and his staff, who hoped Callan could explain discrepancies they had uncovered since the firm's latest financial filing.Einhorn publicly characterized Callan's responses on the call in a negative light and Lehman stock fell sharply.Callan was fired a few weeks later when Lehman reported a $2.8 billion quarterly loss.