from the Comments section on Rule 4-3.3
See the bolded part with the imperative "must not"? Rule 4-3.3 sets forth the special duties of lawyers as officers of the court to avoid conduct that undermines the integrity of the adjudicative process. A lawyer acting as an advocate in an adjudicative proceeding has an obligation to present the client's case with persuasive force. Performance of that duty while maintaining confidences of the client, however, is qualified by the advocate's duty of candor to the tribunal. Consequently, although a lawyer in an adversary proceeding is not required to present an impartial exposition of the law or to vouch for the evidence submitted in a cause, the lawyer must not allow the tribunal to be misled by false statements of law or fact or evidence that the lawyer knows to be false.