It was an offer his client couldn't refuse.

That's how Fried, Frank, Harris, Shriver & Jacobson partner Steven Witzel described the deal offered by the U.S. Securities and Exchange Commission to William Tirrell, a former top executive at Bank of America and its wholly owned broker-dealer Merrill Lynch.

The government accused Tirrell of being directly involved in a massive securities fraud. The bank itself had previously agreed to a $415 million settlement—the second largest penalty in SEC history—for allegedly misusing customers' funds to help it get around a requirement to keep substantial cash on the sideline in the event that it became insolvent.