git status in clean working dir

According to the manual page for git-status (version 1.5.6.3)

       If there is no path that is different between the index file
       and the current HEAD commit (i.e., there is nothing to commit
       by running git-commit), the command exits with non-zero status.

But it doesn't seem to work that way for me.

git status -a 

exits with 0

but 

git commit -a 

exits with 1

Is the man page wrong, or is this a bug? Or, option #3 ?

David

P.S. Please CC me. I'm not on the list.