Facebook said they don't have a policy that stipulates information posted must be true

Thus, they are not obligated to remove such postings.

Facebook said on 24 May 2019 that it would not remove a video that was doctored to depict the US House Speaker Nancy Pelosi slurring her words to give the impression that she is drunk, will remain on the social network because false information alone does not violate FB's rules. 

It further said FB don't have a policy that stipulates that the information posted on Facebook must be true.

Pheewwww... looks like governments around the world are going to sit up and take notice of this stand by FB when the same governments are grappling with the issue of fake news in their respective countries.