That redirect appears to be from the stuff.com server, redirecting the www subdomain to just stuff.com. If you have client-side deployment of Target (at.js on your pages) there is no way to 301 redirect experiences of a test. Target is only called after the page has started loading.
If you have a server-side deployment of Target it should be possible to configure 301 redirects based on a response from Target. It would require some setup on your server to facilitate this though.