Claude Opus 5's three disproofs each employ a different counterexample construction: (1) Conjecture 66 — chain of k vertex-disjoint triangles joined by bridges (forest number vs even degree mode), (2) Conjecture 340 — hand-certified 28-vertex tree (total domination bound), (3) Conjecture 176 — barbell graphs: two complete graphs K_q connected by a path (L_s + b bound). The diversity is significant: a mathematician who can construct counterexamples using three fundamentally different graph families in one day is not finding isolated bugs but systematically stress-testing an entire conjecture collection. The barbell technique is particularly elegant — the closed-form computation makes the counterexample provable by inspection. Opus 5 is demonstrating the kind of mathematical creativity that human researchers spend careers developing.