As most smart people don't use PHP as a CGI module, yes, you shouldn't be worried. If you actually want to make the source viewable, you could make it a .phps file and setup the appropriate association, but there is no way (as PHP is a server side language) to view the PHP page when PHP is installed as a MODULE and not a CGI binary. And even if it is a CGI binary, it is usually automatically called by the association, so basically aslong as the admin's not stupid, your fine.
