Few executives will play a more important role in the current General Motors Co. recall scandal than its general counsel, Michael Millikin. And this week there were some decidedly mixed views about his work.

Millikin’s legal department is dealing with four federal investigations—by the U.S. Department of Justice, the National Highway Transportation and Safety Administration, the U.S. Securities and Exchange Commission, and committees in the House and Senate—over its decadelong delay in recalling 2.6 million cars with faulty ignition switches that led to at least 13 deaths. A former federal prosecutor, Millikin is also coleading an internal GM probe into the problem.