Is there anyway to download a redirecting php file using it's link. I tried just using the right click the link and "save target as" option, but it processes the redirect first and I end up download the index.htm file of the site you get redirected to. Any ideas?

How does the server redirect what - probably your browser? Then it's either an HTML header or a meta-tag within the output which is responsible for the redirection.
In the first case you cannot do anything. In the second you can disable redirections in your browser (or use wget or curl) and have a look at the php output. Which will probably not show you anything interesting except the redirection tag.