Ken White writes about this distinction all the time, and it apparently doesn't apply at all in this case (though he'd just refer you to the FIRE lawsuit threat).

That doesn't justify the post I was replying to at all...

Really? You were saying that the public university is subject to 1st amendment restrictions in this instance, that case says it could be otherwise.

From the note: "In a 5-to-4 decision authored by Justice Anthony Kennedy, the Supreme Court held that speech by a public official is only protected if it is engaged in as a private citizen, not if it is expressed as part of the official's public duties."

No, that case says that they are restricted by the first amendment, and discusses what exactly that stops the from doing. It does not say they might not be restricted by the first amendment.

The original comment I was replying to was arguing that "Google does this, therefore the university can", but that is not the case. Google is not bound by the first amendment, the university is, the argument fails at step 0. That doesn't mean the university can't do it, but it means it isn't a good argument that the university can.

Incidentally, acting as an expert witness is as a private citizen, not as part of the official's public duties, but even if that wasn't the case and this was something that the university could restrict my post would still be correct and the first reply to it missing the point.

point taken, thanks

It seems clear "serve as a witness on this case" is not part of these officials' public duties, yes?

I don't think that's clear, actually. If they are testifying as UF professors, they might be acting in the course of their duties because they are representing the university.

I think that's the argument, anyway, and why if they testify just as concerned citizens there would be no way to stop them.

They're being forbidden by the university to testify.

How can testifying be one of their official duties?

> I could be wrong but it looks like they can testify as citizens, but not paid experts.

Everything I have read from the University and the professors so far indicates they are being denied under any circumstance. Including doing it pro bono at least according to one of the professors: https://twitter.com/ElectProject/status/1454526638578880516 it is being denied by Gray Wimsett, Assistant Vice President of Conflicts of Interest.