This work investigates the origin of the single event hard failures of an advanced commercial FinFET microprocessor induced by heavy ions using a combination of failure analysis tools. It focuses on elucidating the reason behind the hard and catastrophic failures of Intel 5th Generation MCP Broadwell microprocessors due to exposure to ionizing radiation. The failure analysis techniques point toward the same area on the platform control hub (PCH) die. Contrary to the initial (intuitive) hypothesis, the hard failures observed in the Intel 5th Generation MCP Broadwell are caused by 32-nm planar PCH die. These failures do not seem to be anyhow related to the FinFET technology, but the exact physical mechanism has yet to be identified. In conclusion, no critical issues or showstoppers were observed during heavy ion testing of Intel 14-nm Tri-Gate FinFET commercial microprocessors, which would prevent these devices from being considered as future space candidate parts.