Applying the previous link to this case (and not talking about Beck's refusal to give fact evidence, which is a defense he is raising - if his statement is true, there cannot be defamation), claiming that somebody PAID for bombing that was actually carried out, when that person has been cleared by the law, is going to be per se defamatory.
See Richard Jewell case (Atlanta Olympics bombing). Some allegations are so bad (he's a pervert, he's a bigot, he paid for a terrorist act), that there is no need to prove damages.
This is a more general question: If a person publishes what they know to be a material falsehood for the specific purpose of seeing a class of people they know to be telling the truth publicly maligned, is that libel/defamation against that class of people and/or the individuals within that class of people? Basically, is taqiyya a form of libel - whether it be Muslim, liberal, political, media etc taqiyya. lying for a cause with the intent of seeing your enemies FALSELY maligned?