User blog comment:Willbachbakal/(Champion Rework) Ashe, the Frost Archer/@comment-5035765-20140809044641/@comment-1330314-20140809141754

The reason I wanted the effect to revolve around her ability-based CC, rather than just her abilities, is because I want the shatter effect to only be available while her target is actually CCed through her abilities. Ashe's CC has a variable duration (my version of her Q has a root that lasts from 1 to 2 seconds, her ult's stun duration increases with distance), so it makes more sense (as well as better thematic consistency) to base the shatter proc on her abilities' crowd control.