Zuckerberg: "We do not want to be arbiters of truth ourselves..."
Zuckerberg (paraphrasing): "We'll penalize sites we deem to contain inaccurate information."
To be clear, I think the latter stance is appropriate and reasonable in this case. It's also Facebook's right to police content on its system as it wishes. However, I think that in this and many cases, Zuckerberg is being somewhat disingenuous.
This statement in particular is not a huge example, and the article itself is crying wolf somewhat, but it's a mistake to assume good faith from Facebook at this point.