I've already read and commented on that article, and most of the comments reflect the general sentiment of most people, which is that mainstream news isn't credible either.  If we applied the EXACT same standard that your colleague just outlined, or the SPJ code of ethics, we would have to determine that the Washington Post is fake news after reading the "Russian fake news" story (which is one of THOUSANDS of examples).  Seriously, all the tools that we would use to spot fake news, all of the arguments she made, would equally apply to this WaPo article or thousands like it.  

The problem is that the people are starting to realize that the news establishment is not a credible source of information, any more than the US government is a credible source of information when it comes to foreign policy.  Big Media in America is largely indistinguishable from state-owned propaganda like RT.  RT is more credible than CNN, that's for sure.

https://en.wikipedia.org/wiki/Operation_Mockingbird