Retrieval-augmented question answering is supposed to ground answers in evidence, but a new arXiv preprint (2610.27114) highlights a failure mode: the correct answer can be present in the retrieved passages and the system still answers incorrectly. The problem arises when a competing answer satisfies only part of the question's requirements while being mentioned often enough in the evidence to dominate.
Such qualifier-sensitive questions—where the user attaches conditions or constraints—are especially vulnerable. The paper introduces "joint constraint aggregation" as a way to handle these cases, though the abstract leaves the technical details to the full text.
Because this is a single source, there are no independent results to compare against. The contribution is framed as a targeted fix for a specific RAG weakness rather than a general overhaul of retrieval-augmented systems.