A construction worker who lost his job on Apple’s new campus because of a 2008 felony conviction said he filed a complaint with the EEOC alleging discrimination. The complaint could trigger an investigation of the tech giant’s hiring practices, which became the subject of controversy when Apple was barring felons from construction jobs. If the commission sues, it could chart legal territory regarding criminal histories and employment. The commission has sued companies like BMW and Dollar General for their hiring practices involving criminal background checks. Those cases are still pending. But experts say there have been relatively few legal challenges. “It is somewhat an underdeveloped area of the law,” said Lisa Klerman, director of the USC Gould School of Law Mediation Clinic.