Clicking Show All adds next tag

When I use the Add Tags action and click in the entry box, the list of tags appear. If there are more than 8 tags, the list is truncated with the entry "Show All" at the bottom of the list. When I click on the Show All entry, whatever tag should be in that position is added to the entry box.
Here is a series of screen shots showing the problem.
Top : the tag list with Show All at the bottom
Middle : the tag list after I clicked the Show All entry. The Excluded tag is added to the entry box
Bottom : the tag list after removing the Excluded tag from the entry box. It returns to the list position where Show All was

Here is a series of screen shots showing the problem.
Top : the tag list with Show All at the bottom
Middle : the tag list after I clicked the Show All entry. The Excluded tag is added to the entry box
Bottom : the tag list after removing the Excluded tag from the entry box. It returns to the list position where Show All was
