Just thought I'd add one of my favorite examples of this: 

After the infamous 2017 riot in Charlottesville, VA, Snopes concluded that the claim that police were ordered to stand down was false.  Initially, they arrived at that conclusion solely based on denials of police spokespersons - which is an obviously laughable standard in itself.

A few months later, however, a state investigation into the events revealed that at least 2 employees of the police department witnessed the police chief command “let them fight, it will make it easier to declare an unlawful assembly.”  So, Snopes issued an update on the claim.  Did they change their conclusion?  Of course not.  They simply clarified that since the police chief didn't actually use the specific words "Stand Down", then the claim that he ordered police to stand down is still false.