It appears that Google is showing unverified Twitter profiles in their Google Knowledge Graph panels in Google Search.
As an example search Gabe Newell, which shows an unverified Twitter account on the panel (incidentally it's not even his real Twitter account):
From Google's developer documentation (and all other sources I've read), this should not be possible - because Twitter supports verified accounts, Google will only show verified accounts:
Google only shows verified profiles for sites with a verification process.
Is this just an unexplainable glitch or has Google changed their policy and not yet updated it in their documentation? If the latter, are there any sources, official or unofficial, that acknowledge or describe this change in policy?