You fooled me. I’m fine with your later “there’s no evidence of a conspiracy.” But saying “there’s no conspiracy” is indeed a claim in casual speech.
The potential evidence of a conspiracy is that the professors were denied permission to testify, when, as you point out, they’ve been allowed in the past. What changed?
Correct, your claim “There’s no conspiracy here” is something you don’t know and can’t prove, therefore is an unjustifiable claim.