error(?) in "man git-stash" regarding "--keep-index"

  toward the bottom of "man git-stash", one reads part of an example:

  # ... hack hack hack ...
  $ git add --patch foo            # add just first part to the index
  $ git stash push --keep-index    # save all other changes to the stash
                                              ^^^^^ ???

i thought that, even if "--keep-index" left staged changes in the index, it still included those staged changes in the stash. that's not the impression one gets from the above.

rday