MD, I think you are mischaracterizing the quality

MD, I think you are mischaracterizing the quality of the word "MAY" in the context of covid transmissibility.

The success of contact tracing proves that covid is transmitted from one person to another.

So how many ways can a covid molecule get from one person to another?

I can only think of some ways that a covid molecule can get out of the first person: tissue loss (like bleeding), respiratory excretions, sweat, urinary excretions, and fecal excretions.

The high transmissibility of covid combined with the effectiveness of personal protective equipment like masks, gloves, and gowns would seem to prove that the transmission is through touch or through the air.

I guess your point is that the masks are possibly unnecessary because the main transmission might be through skin touching skin?

It is a practical impossibility to label a covid molecule and track its path from one person to the next.

The only transmissibility data that we will ever have is from contact tracing: the physical circumstances of the contact will constitute the proof of the mechanism of transmissibility.

So it would seem to me that extant contact tracing reports have already proven the point.

What else is there to do?

The article you posted has no "MAY" in the context of person-to-person contact. The only "MAY" is in the context of respiratory secretions, I suppose leaving open the possiblity of touch transmission rather than respiratory secretions. But even that seems a huge stretch.