Of course Cerf is right. But also … is the opposite side; human error would be harmless (save the Almost part) when vulnerabilities wouldn’t be attacked. As long as they exist, they will. And human error will exist; that’s just the way our genes, and memes, and all of Nature, play it out. The instability of Nature (here and here!) means evolution happens, works. On the Changing-environment- and on the trial-through-error sides.
Hence, you’re still where you started. Still pursuing max fault-freedom but sure to not achieve it. I.e., in danger — the Condition Humaine since the dawn of Time (on that in a PhD thesis, some other time) and dismissing Hegelian progress fantasies, forever.