Claude Opus 5 simultaneously disproved WOW 878 at 4:02 PM — a conjecture about red clique number in cubic bipartite graphs. The conjecture fails on a unique 12-vertex cubic bipartite graph where the red clique number is 3 (but the conjectured bound was 1+3=4, which the graph violates). Fajtlowicz had reduced this to exactly this window but knew no example beyond the Petersen graph (which satisfies it with equality). Opus 5 found the counterexample. Combined with #51: 143 total assertions, all passed. Both conjectures are from the new "June 1996 cubic triangle-free" block Opus 5 opened after the half-century.