The refusal message fell through to the chi^2 branch whenever the
systematic-b balloon veto was the binding test, so it reported a chi^2 ratio
that did not justify the refusal at all - on one battery crystal it printed
"merge chi^2 is 1.25x the subgroup's (bound 1.85)", i.e. a number comfortably
inside its own bound, as the reason for processing in the lower symmetry. A
diagnostic that names the wrong cause is worse than none: it sends the reader
after the wrong statistic.
Report the b test when it is what fired, with both b values and the bound.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>