I guess it says something that "You won't know who to trust" (as Gregor said in Sneakers). And, of course, "stocky guy in camo with a bushy half-gray beard" is not nearly as identifiable a thing as one might think.
Being meta, I trust Russia less in this than I trust the Western media that might have a US-sponsored mission against Russia. Not that both aren't probably in play here.
Ukraine’s Pro-Russia ‘Militia’ Look Suspiciously Like Veteran Russian Soldiers
In a totally unsurprising development, there seems to be mounting and significant evidence that pro-Russia Ukrainian separatists are probably actual Russian soldiers.
Listen to what Putin has said publicly. It's not a hard denial. It's a wink and a nod to the fact that these are his guys.