playKeyEvent's `if hasModifier { return false }` bailed on BOTH key-down and key-up. On key-up with Ctrl (or Option) still held it returned before the note-release path, stranding the sounding note/chord — Cmd was unaffected only because Cmd isn't in `hasModifier`. Gate the passthrough on `isDown` so key-ups always reach release, matching the method's own "release is checked on EVERY key-up, not gated by Ctrl" contract. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>