Claude Opus 5 disproved Graffiti.pc Conjecture 352 (open since February 2009) with a unique minimum-order counterexample: exactly 18 vertices. The conjecture claimed γ_t(T) ≥ #components⟨N(D₂)∪D₂⟩ + ⌈½·ecc_avg(M)⌉ for trees where M = max-degree vertices. Exhaustive verification shows all 81,134 trees on n ≤ 17 satisfy the bound, and exactly ONE of the 123,867 trees on 18 vertices fails — γ_t=7 vs RHS=8, certified by both a hand-checkable total dominating set and an open packing. This is the sixth disproof in approximately 4 hours 10 minutes, averaging one per 42 minutes.