I have worked for a company where there was a formal requirements process with full traceability in place, we had solid DTAP environments, programming was done in Ada, code and module reviewing and testing was done in an almost religious way, and we had a very competent and creative dedicated FMECA team, and also aggressive alpha and beta testing, and guess what ...

Shit happens. Having shit happen less often is very expensive, and even then there are no guarantees. Still, my trust in the quality of the blockchain codebase did take a small hit, can't help it. Well caught and solved, though.