Is there some meaningful distinction here that means false allegations about an organization of humans should go unrefuted, but false allegations about a single human should be refuted?
To me, false allegations against individuals are more serious than false allegations against organizations for a few reasons. First, I care about the well-being of organizations only to the extent they positively impact the well-being of humans (or, to a lesser extent, animals). Second, a single false allegation against an individual human seems to be able to have a much more damaging effect than one against an organization.
I suspect this is a well-worn topic and that I would consider many of the other objections to corporate personhood to be "meaningful distinctions".
Even if it were a private organization, such allegations could directly result in harm to the human owners. For example, false allegations about bad food at a restaurant would mean the human owners and employees lose money. In much the same way, false allegations about a human might result in them losing their job.
I don't think we're going to be able to settle this argument here, so I'll just leave it at that.