This document summarizes a study investigating factors that led to an audit failure at Cadbury Nigeria PLC. The regulatory authority found the auditor, Akintola Williams Delloitte, negligent, incompetent, and lacking professional skepticism. The study identifies several possible causes, including the auditor's long tenure of over 40 years which may have impaired independence. Providing non-audit services was also identified as compromising independence. The audit failure cost investors billions and damaged confidence in the capital markets. The study recommends mandatory auditor rotation and prohibiting non-audit services to improve audit quality and prevent such costly failures in Nigeria.