Sorry, I was unclear. By "story" I meant the specific story about the machine they attempted to wipe clean but that still remained infected somehow. The theory that the virus could communicate over air gaps would be irrelevent to that specific story, because if we assume that the computer was still infected, jumping air gaps is irrelevant to what was observed in that specific instance.
In other words I'm agreeing with you that the Ars article was misleading. But my initial comment was not meant to be critical of Dragos or anybody else. It was an honest, uncharged question about how my reading of the Ars article would be possible, even theoretically. The answer (it sounds like) is that the Ars article misled me about what Dragos was actually claiming.
I think the point is that anyone with an ounce of technical competence knows that the claim of formerly a normal computer being infected via sound is patently absurd, so even bringing it up is unnecessarily distracting from the discussion at hand.