SAN FRANCISCO — The U.S. Court of Appeals for the Ninth Circuit sounded skeptical Monday of an SEC claim that stock transfer agents are strictly liable for the illegal sale of unregistered securities, especially if the agent relied on counsel’s advice.

In what Judge Susan Graber described as "an interesting and challenging case," the court sounded reluctant to hold transfer agent Helen Bagley liable for securities fraud as a matter of law in a diamond mining scam that cost investors $64 million.