The line between "spit droplet" and "airborne" seems to be kind of vague at best to me.
I would like more clarification on this issue, too.
I can make the distinction between water as an aerosol and water dissolved into the air. An aerosol is small to super-tiny droplets. Anything form sea spray to fog. Water dissolved into the air presents itself as absolute humidity. The two act on the hardware I care about in different ways.
But as to the difference between "airborne" and "aerosol" in the medical/biological sense, I could use a hint.
Quite a big difference between "hasn't happened yet" and "unpossible."
That's the thing: IIRC, it
has happened. In a USAMRIID Level 4 protocol lab. They could not explain
how, though(1), so claims of "proven" seem premature while at the same time "hasn't happened yet" can no longer be claimed. Not a happy place to be, but there you are.
I am not referring to Reston Virus.
But, again, you don't see any goobers form USAMRIID running in front of a camera to claim it can't happen.
(1) And, yes, poo and urine flinging was postulated, as well as some sort of aerosolized bodily fluids. They could not hammer any of them down to their satisfaction.