The problem is that the guy made up the story and no one verified when or if his mom died. Think about it, besides all the reporting about the event, liberal celebrities went off on tweets and of course on all the late-night shows.
Millions of people heard about an evil thing President Trump did and hardly anyone corrected their stories. If you were Trump how would you feel about the press?
This is just one of hundreds of stories that were either made up or run without proper vetting because of a political narrative. How many times over the last eight years of Obama did they incorrectly report negative things about him? I think this says a lot.