It is also possible they told him that if he didn't resign, he would be terminated. From the article, "No employer shall coerce or influence or attempt to coer

It is also possible they told him that if he didn't resign, he would be terminated. From the article, "No employer shall coerce or influence or attempt to coerce or influence his employees through or by means of threat of discharge or loss of employment to adopt or follow or refrain from adopting or following any particular course or line of political action or political activity." Unless he wants to make a mess for Mozilla (and I don't think it sounds like he does), we'll probably never know what really happened.