Are you an SEO consultant or another type of consulant?
More of web analytics
-Have the backlinks changed?
Backlinks have dropped significantly after the redesign and they changed the URL. They did not go back to ask other sites to link to the new URL. They also did not do a very good job in redirects (e.g. many of their internal pages were redirected to the homepage, not to the new URL of the page).
-Did they do any link development?
No. The don't do any links. Just organically. They're more focused on traditional marketing - with a huge communications team divided into TV, radio and print. They now have social media, but not really SEO.
-Do they sell/buy links?
No. They do buy advertising spots (e.g. ads in the DC Metros, banner ads in Drudge, etc. but not links).
-Have you checked to see if the traffic loss is due only to a drop in Google referrals?
Yes. Only Google. Overall traffic dropped only 18%, as there are other sources of traffic. Google dropped 50%
-Have you scanned for malware or signs of hacking?
-Have you checked to see if another site stole content?
Yes. Many. And they have never been one to file DMCAs at all.
-Are there any 302 or 301 issues?
One issue I've seen is that for some searches, an internal URL that they use to view any changes of their website (e.g. instead of www.URL.com the internal URL is origin.URL.com) is now visible in Google. Instead of the www.URL.com version of the page, it is the origin.URL.com of the page that is showing up. The www. URL is nowhere to be found