CRPC 4.1:

In the course of representing a client a lawyer shall not knowingly:

(a) make a false statement of material fact or law to a third person; or

(b) fail to disclose a material fact to a third person when disclosure is necessary to avoid assisting a criminal or fraudulent act by a client, unless disclosure is prohibited by Business and Professions Code section 6068, subdivision (e)(1) or rule 1.6.