I noticed this when fiddling around on one of my questions. Steps to reproduce:
- Go to a question (this one), and use the T (10k only) shortcut to open the tag editor.
- Add any tag (although the status-review one is preferred), click "Save Edits", let it give you the error, then cancel it.
- Watch your hat fall off!
I also did this on this post, and accidentally pulled Anita's hairdo off. With apologies to Anita, can we fix that?