I figured RT would be the most skeptical news outlet in this case, and if RT was reporting it, then Russia at least tacitly approved of giving credibility to the allegation. If Russia didn't think the alleged Gulen link was at least plausible, RT never would have floated it.
P.S. I predict a conspiracy theory will surface claiming that Putin arranged/ordered the hit on purpose. Reasons given could include:
- eliminate an untrustworthy/ expendable diplomat (who may have privately disagreed with Putin and/or been a liability in some way),
- create a reason for Erdogan to seek to extradict Gulen/ tighten internal controls even further (possibly as part of a longer term quid pro quo between Putin and Erdogan)
- create world sympathy for Russia in the wake of Aleppo (i.e. to disrupt or reverse the recently prevailing global narrative of "Russia bad; Aleppo victim"),
- coerce (guilt-trip) Turkey into being more cooperative with Russia, or if not, it gives Russia an excuse to operate more freely/ unilaterally within Turkey for "counter-terror"
Not that such a conspiracy theory is actually true. But I basically view Putin as Machiavelli in the 21st century - who is above nothing if it helps him achieve his objectives.