Lewis Ferguson III was ready to step down as GC of the Public Company Accounting Oversight Board when the agency got hit with a potentially life-threatening lawsuit. Now Ferguson says he’ll stay on, at least for a while, to defend the PCAOB in a case he says may go to the U.S. Supreme Court.

Previously a partner at Williams & Connolly in Washington, D.C. for 23 years, Ferguson became the PCAOB’s first general counsel in 2004. The private nonprofit agency was created by Congress as part of the Sarbanes-Oxley Act. Its job is to oversee auditors of public companies and ensure that there won’t be another accounting scandal like the ones at Enron Corp. and elsewhere. The Securities and Exchange Commission appoints the board members of the PCAOB, though its budget is independent of the SEC.