The Pump Barrel experienced an internal structural failure at the bimetallic connection, causing it to separate while under normal laydown loads. The degradation occurred beneath the coupling and could not be identified through routine visual inspection on the rig floor. The completion assembly contained dissimilar metals, making the connection susceptible to long-term galvanic corrosion and loss of structural integrity. No engineered secondary containment or physical barrier was available to arrest the tubular once the connection failed. The task required personnel to manually guide the load through the V-door, creating line-of-fire exposure during a dynamic lifting operation The travelling block continued moving while personnel were returning to the designated safe zone. Historical failures and potential integrity concerns associated with similar completion assemblies were not highlighted within the work instructions or well program.