That's an exaggeration by far: only the tiniest subset of systems can kill people if they fail. Hacks happen by the millions with headaches being the main result along with lost time and money. Even most security-critical systems are the same with the main targeting being done for espionage (data theft). High assurance security focuses on what can get people killed (esp military use) with an emphasis on tools such as these. I've never seen a mainstream FOSS or proprietary product show evidence of an EAL6+ development process, though. Even security community largely throws stuff together plus some code review.

Best to keep it real about risks so your solutions match requirements. Most companies are happy to sell patches to broken software or offer software that passed many checklist items for compliance. They have lawyers for the rest.