Apparently Musk was interviewed by a lawyer at SEC who then went on to join a law firm, which had Tesla as a big account/client. When Musk got to know that the lawyer was working at his "consulting" law firm, he asked them to fire him, to which they flipped the bird. He then threatened to take the work from them and give to another firm. All this for the "insult" of being interviewed/questioned by the lawyer.
Very well done by the law firm (Cooley) (ahem!!). Rare move, but Musk put in his place.