On the section of its Web site describing its labor and employment practice, O’Melveny & Myers says that “much of our work and advice is preventive in nature, conducted with the goal of minimizing or eliminating the employer’s exposure to liability and costly litigation.”

But with a Monday ruling, a three-judge panel of the 9th U.S. Circuit Court of Appeals said that the firm didn’t live up to its marketing when it tried to impose an aggressive arbitration agreement on its employees.