A violation of Section 6157.1, subdivision (a) or (b) of Section 6157.2, or Section 6157.3, 6158, 6158.1, or 6158.3 by a licensee shall be cause for discipline by the State Bar. In addition to the existing grounds for initiating a disciplinary proceeding set forth in a statute or in the Rules of Professional Conduct, the State Bar may commence an investigation based upon a complaint filed by a person pursuant to Section 6158.4. The State Bar’s decision pursuant to subdivision (a) of Section 6158.4 shall be admissible, but shall not be determinative, in any disciplinary proceeding brought as a result of that complaint.