ScriptAlias /php/ "/usr/bin"
I, too, was able to reproduce this error, after following the instructions to the letter.
Upon investigation, I found this in the error_log:
"client denied by server configuration: /usr/binphp-cgi"
I adjusted the line ScriptAlias /php/ "/usr/bin" to be ScriptAlias /php/ "/usr/bin/" (notice the trailing /), and it resolved the issue.
Hope that helps!