You are correct - it is very frustrating to be asked to prove a negative.  The Washington Times article is incorrect.  They did not print a retraction.  What would Wikipedia editors consider a verifiable source that something did NOT happen?  Does a link to the "leadership" page from BGR's website, without General Pace's name, "prove" he doesn't work there?  An unsigned contract? Even a letter from BGR indicating General Pace would not appear to meet Wikipedia standards for a public, verifiable source.  The same goes for the article that said he left 7 notecards.  He recited 7 names during the retirement speech, but he only left 4 notecards.  Could a photo of the 4 cards serve as a source?  But how does that "prove" there weren't three others outside of the frame?  What would you recommend General Pace do to get these errors of fact corrected?  I appreciate any ideas/help you can offer.