I wouldn’t trust the author as far as I could throw him, but it was a Russian disinfo campaign, just not in the way the media reported it. The Russians successfully fed made up material to Chris Steele. And they also fed info to Hillary through Cody Shearer (who is now conveniently dead and can never be questioned), who fed it to Sid Blumenthal (who is now also conveniently dead albeit he was old enough to age out without help.)
It was the Brookings Institution that fed false information from Hillary campaign through Danchenko to Steele. Steele pretended not to know the info was fake stuff from the Hillary campaign. Everyone was careful to preserve some plausible deniability, or at least enough to bring the MSM to their defense, and a partisan DOJ to ignore the facts.
Blumenthal is very much alive.