Ernie Ruiz, a driver for Sysco Food Services of San Diego, was accused by a co-worker of brandishing a knife in an argument over a jacket. Ruiz was sent home, Sysco employees called police, and the next day, Ruiz—who denied the accusations—was terminated for violent and threatening conduct. He sued for defamation arising out of the investigation and its aftermath. But now a California appeals court says Ruiz must arbitrate his claims under an arbitration provision in the union contract covering his employment. That’s because his defamation claim derives from his right under the union contract to a fair and full investigation. And whether Sysco failed to do this must be determined through an arbitrator’s interpretation of the union contract’s terms.