The import finished, logged 'processed successfully,' and returned zero errors. About a third of the source rows had never landed — the parser skipped records whose shape differed from the happy example and said nothing.
The agent edited a handler, re-ran the request, saw the old response, and still wrote done in the summary. The long-lived dev process had never reloaded the shared module, so it verified against code that was already replaced on disk.
The agent renamed the class, updated every reference, and CI went green. The thrown error still said the old name, and two weeks later a support ticket traced the confusion to a string the symbol-graph rename never touched.
The agent guarded the user-facing call site and the test went green, but the same helper sat behind an internal batch job the fix never touched. Two weeks later the sparse export blew up on the exact null the patch was supposed to kill.
