Is an attorney who enters into a business transaction with his clients in writing to advise them to seek the advice of an independent lawyer of the client's choice?

Rule 3-300 of the Rules of Professional Conduct requires attorneys who enter into business transactions with their clients to first advise them in writing to seek "the advice of an independent lawyer of the client's choice." The attorney is further obligated to give "his client 'all that reasonable advice against himself that he would have given him against a third person.' " (Beery v. State Bar (1987) 43 Cal.3d 802, 813, 239 Cal.Rptr. 121, 739 P.2d 1289.)