When global smart groups are deleted from the sidebar they’re temporarily persistent until another selection is made. How to reproduce:
• Create a Smart Group and drag it to SMART GROUPS in sidebar to create a global duplicate
• Select new SG in sidebar and delete it with Delete under the context menu
• BUG: The SG disappears from the sidebar list, but its view in the current window remains
I’m struggling to see how it would ever be useful (to me) instead of counter-intuitively confusing. It doesn’t make sense for the view of a deleted Smart Group (or any group) to remain visible, at least when compared with deleting (smart) folders in Finder.