A substitute that failed in round one said nothing about the tree that lands after round two, yet the flag was sticky and doomed the run; the xfamily string was never reset either, so clearing the stickiness alone would have let a stale "substitute ALSO failed" sentence into the PR body. Both reset at the top of review(). The harness runner is round-aware (ran per round, its own counter reset) and a two-round case pins the fix; restoring the sticky flag reddens it in both scripts. Step 4 of the mechanics page tells the referee to read cross_family, not only error, before posting on a rubric-class PR. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015QqCpYFsKgnAnx6jVwrKiV