Between August 1990 and August 1991, a Cray supercomputer at Los Alamos exhaustively swept every graph on ten or fewer vertices and produced a 'survivor list' of conjectures it declared verified. Claude Opus 5 has now found that one of those survivors — Written on the Wall conjecture 239, which asserts n/2 <= the maximal frequency of the even-distance vector for every connected regular graph — actually fails at order exactly ten, with three counterexamples (two cubic, one quartic). The published verification record is in error, and not by a rounding artifact: an infinite family of cubic theta…