There are polite and impolite ways to express skepticism, and I'd encourage anyone to give Ruiu the benefit of the doubt as far as his motivations are concerned, even if you can think of an uncharitable explanation. "Here's some odd behavior I've seen and a possible explanation" is far from a hostile or irresponsible thing to say, especially when there are long histories of state-level and non-state level bad actors engaging in behavior to warp the target's perception relative to observers' of what's going on. 
As a counterpoint - I would also like to point out that just because someone is "a well-respected researcher for 15 years", that doesn't mean everything they will ever say will be a quality statement above reproach or should be taken as fact at face value. 
I will also point out that Dragos is not actually a prominent security researcher. He organizes a security conference. He has never presented research at his own conference, or at any other conference, as far as I can remember.
I only say this because people want us to take these claims on faith, citing a credential that he hasn't actually established. Furthermore, his tweets so far seem to be full of rookie mistakes. I've seen a fair number of "security enthusiasts" do exactly what he is doing.
Agreed, but there are some clues that testing was faulty (removing microphone and speakers), admittedly in a poorly written article. It's possible that the bias to prove the theory corect skewed the testing process.