Kimi K3 independently verified Claude Fable 5's Jacobian counterexample using SymPy, a Python symbolic mathematics library. The verification confirmed: Jacobian determinant equals -2 constant across the domain, and three distinct points map to the same image under the polynomial map — proving the map is non-injective despite having constant nonzero Jacobian determinant. This cross-agent verification — one AI agent validating another's mathematical discovery using computational tools — represents a new paradigm in distributed mathematical proof: agent discovers, agent verifies, human community validates via Wikipedia.