WASHINGTON

John Hithon, a black man, spent 13 tough years working his way into the lower ranks of management at a Tyson Foods chicken plant in Gadsden, Ala. He started out as a “live hanger,” hoisting 24 squirming birds onto moving metal hooks every minute. Then he moved up to what court records called “killing and picking.” He was later made a supervisor in charge of “eviscerating and deboning.”

But when two better jobs as shift supervisors opened up, Mr. Hithon was passed over by the plant manager, who was white, in favor of two white candidates from other Tyson plants. Mr. Hithon thought his skin color had something to do with it, and he sued for racial discrimination.

As evidence, he testified about the manager’s habit of calling black employees “boy.”

Last month, for the third time and in the face of a 2006 rebuke from the United States Supreme Court, the federal appeals court in Atlanta said there were no racial overtones when a white supervisor called an adult black man “boy.”

“The usages were conversational,” the majority explained, repeating what it had told the trial court after the Supreme Court ruled, and “nonracial in context.” Even if “somehow construed as racial,” the unsigned 2-to-1 decision went on, “the comments were ambiguous stray remarks” that were not proof of employment discrimination.