wrong logo displayed when using subtheme and CDN module

I ran into this issue when I created a subtheme of Clean, and attempted to use the CDN module. Instead of using the proper subtheme logo (or a custom one), the site kept on defaulting to using the default Drupal logo included in Clean. I've pinpointed the error to the following code:

file_exists($logo_path) ?
      $image = theme('image', $logo_path, $site_name) :
      $image = theme('image', $path_to_clean .'/logo.png', $site_name);

The CDN module takes a normal path like '/sites/all/themes/clean_subtheme/logo.png' and rewrites it like this 'http://cdn.com/sites/all/themes/clean_subtheme/logo.png'. However, since the URL isn't a local file, the file_exists call fails, and so Clean defaults to using the Drupal logo, instead of the correct logo on the CDN. To fix this, I've removed the file_exists call, and simply assumed that if a logo is configured that it exists.