I'm not aware of any false statements that Snowden made, or any doctoring of the NSA documents he provided. (Senators and other officials have confirmed the legitimacy of at least some, as has a federal indictment.)

But journalists can and do make mistakes interpreting the documents. Here's one example of a report trying to set the record straight: http://news.cnet.com/8301-13578_3-57588337-38/no-evidence-of...