Initially I posted this as a comment on Catarina Dutilh Novaes' post below, but at Eric Schliesser's suggestion, I am making a separate post of it, with a couple of small changes:
The EIC response is a scanned pdf, which was initially posted at http://www.syntpetition.info/. As far as I can tell, this is a website with one item only. This is clearly a tactic to make the response as obscure and invisible as it can be. There is no link to this site from the official Synthese site, and the response to the petition is not posted on the official site, though a lot of bumpf is.
The response says that there were no legal threats from Beckwith's side, but implies that there were quasi-legal threats from others. The EICs say that they are constrained by these threats, but do not say how. (Why can't they tell us why they object to Forrest's piece, for example?) The EICs do not deny (though they also do not clearly confirm) that the Guest Editors were assured that no editorial statement would be published. Their statement does not explain why Beckwith's reply to Forrest was not refereed. It does not apologize, though it says that editorial scrutiny policies are being reviewed. (I take this to be a renewed dig at Forrest, not an acknowledgement that they were wrong to publish Beckwith's response in the form that they did.)
A passive aggressive gambit, in my opinion.