If there is no hidden questions left then Show Only Bookmarked menu item shouldn't contain tick. Otherwise user has to choose the menu item twice to hide them again.
How to demonstrate:
1. Open Configuration Editor
2. Enable bookmarks
3. Choose one question as a bookmarked
4. Select "Show only bookmarked question"
5. All not bookmarked questions will be hidden in ...
6. Double click on ... they will be shown. Tick will remain for Show Only Bookmarked menu item although no hidden questions are left .