Bad answer to a bad peer-review I submitted a paper together with other people to an important journal. A couple of days ago we received the answer from the editor and the paper was rejected (I was 3rd author) with very bad comments. One of the reviewers wrote that the paper was lacking innovation or originality. Another one sent us more than 20 comments. To be honest the comments weren't really appropriate because we did particles loaded with gold or FITC and one of the comments was "It seems that the FITC and gold are encapsulated inside the nanoparticles, not the other way around." He did not understand a lot but still, he also did a lot of interesting comments. 

Anyway, the main author yesterday emailed the editor saying that the reviewers do 
not have enough knowledge to correct this paper, that they are unqualified and that people like this should not correct this kind of work. This person sent the email to the editor without speaking to any other authors, therefore we discovered today what happened and some of us still don't know. 

Do you think that the journal, following this email, can do something to the authors of the paper? Like, e.g., sue us? or ban us to publish there? or stuff like this?

What should we do now?
What do editors do when authors send them angry emails questioning the competence of the reviewer? When I edited a journal, if the author provided technical arguments against the reviewer's comments, I would forward those to the reviewer(s) and see what they say. If they didn't, I would usually say something generic about our faith in our peer review process and apologize that we cannot accept the paper. Either way the dispute does not usually escalate beyond the three of us (author, editor, reviewer).

Filing a lawsuit would be unprecedented. Banning you from submitting is more conceivable, but still unlikely. After all, it's to their advantage that authors submit potentially-publishable papers there. If it happens my guess would be that the author wrote something that crosses into the realm of personal attacks: for example, "tell your reviewer to take a gun and shoot himself".

In any case it is not something to worry too much about - after all it's not you that sent the bad answer - unless the author did write personal attacks, in which case you could send the editor an email distancing yourself from the author's behavior.