Whether a satisfied verdict was downgraded because grading was incomplete.
True when the grader twice returned a criterion count the coverage check
rejected, and result was rewritten away from satisfied as a result.
The rewrite target is needs_revision. On the final iteration result is
then rewritten again to max_iterations_reached while this flag stays
True, so (max_iterations_reached, unverified=True) is a reachable pair.
A needs_revision verdict that under-reports is left alone. It claims
nothing that needs blocking, so this stays False there.
