MULTI-EMPLOYER WORKSITES – DETERMINATION OF CITABLE EMPLOYER Cal. Code Regs, tit. 8, §§ 336.10 and 3329(d) (2015) – Employer appropriately hired, supervised, monitored and followed up on the work of a subcontractor, and the hazard that caused an injury was unknown to all due to its inadvertent creation by the subcontractor’s employee. Employer showed that it acted with due diligence in relation to the violation and, thus, established the affirmative defense available only to controlling employers.