While I have not been a great fan of civility movements in professional discipline, even I have to acknowledge the legitimacy of professional discipline for the Toronto lawyer, Julia Ranieri who, after a verbal disagreement with a client who wished to change lawyers, punched her client in the nose, breaking it. The lawyer was charged with assault, and then instigated a private prosecution against the client. Both ultimately did not proceed to trial, with the lawyer agreeing to pay the legal fees of the client in relation to the private prosecution. After a disciplinary hearing before the law society, Ms. Ranieri was suspended from practice for 10 months; she had a history of other disciplinary issues.
I would argue though that the problem is not that the lawyer was uncivil, but rather that she breached her fiduciary obligations in a fairly dramatic way. The rules may not specify "and putting the interests of the client first includes not physically assaulting him or her when she wishes to change lawyers" but that seems a legitimate inclusion. And I think would apply whether or not there was a basis for Ms. Ranieri's pursuit of the private prosecution.