[Bug?] .git visible in git-status

I've recently stumbled upon interesting issue - .git/* files occurring
in the git-status output.
Let me elaborate:
1. When running

git status -s

no .git/* files are displayed
2. When running:

git status -s .git

only an empty line is printed out
3. But when I run (for example):

git status -s .git/HEAD

I get
?? .git/HEAD
Files are listed also when -s option is not present. When providing
.git/* all of the files under .git directory are printed.

I don't know if this is desired behavior, but i guess it's not.

Best regards
Radek