In other words, serious reporting (as opposed to opinion pieces) treated lies as though they were truths. This could only be considered harmful.
There has been quite a lot of discussion around this. See, for example:
The Death of 'He Said, She Said' Journalism http://www.theatlantic.com/politics/archive/2016/09/the-deat...
Big lie, little lie, and the media’s role in telling the difference http://www.cjr.org/criticism/trump_birtherism_lie_media.php
It’s Not Too Late for the Media to Fix Its Election Coverage: A final plea for sanity in how we report on Donald Trump and Hillary Clinton. https://newrepublic.com/article/136848/its-not-late-media-fi...