This research release presents a certificate-backed candidate counterexample to the TxGraffiti Conjecture 15/3. The package exhibits a connected cubic graph on 50 vertices for which the minimum cardinality of a maximal matching is 15, while the independent domination number is 16, so the proposed inequality fails for this regular graph. The release also develops an exact formula-graph identity based on bilateral deficiency and a conditional order threshold for the subclass of cubic graphs with a dominating induced matching. The evidence package includes the graph in multiple encodings, explicit witnesses, a proof-tree certificate, exhaustive deterministic checks, source code, a pinned container definition, and a machine-readable claim and assurance map. All bundled theorem-critical checks pass in the recorded environment and from a clean extracted copy. It remains an unrefereed candidate: the exact release has not been independently rerun, independently reimplemented, formally verified, or conventionally peer reviewed. The graph is a public predecessor object, and the release makes no claim of first discovery, unrestricted order-50 minimality, uniqueness, or secured novelty priority. This is an Evidence Press audio briefing, released 8 August 2026. The full paper, evidence supplement, source archive and replay commands are linked on the release page. The audio is an AI-generated voice summary; it is not additional mathematical evidence.