Every attorney who either directly or indirectly buys or is interested in buying any evidence of debt or thing in action with intent to bring suit thereon is guilty of a misdemeanor. Any attorney who in any proceeding before any court of a justice of the peace or police judge or other inferior court in which he appears as attorney, willfully misstates any proposition or seeks to mislead the court in any matter of law is guilty of a misdemeanor and on any trial therefor the state shall only be held to prove to the court that the cause was pending, that the defendant appeared as an attorney in the action, and showing what the legal statement was, wherein it is not the law. If the defense be that the act was not willful the burden shall be on the defendant to prove that he did not know that there was error in his statement of the law.