|(a) Irrelevant, immaterial, or unduly repetitious evidence shall be excluded. The rules of evidence as applied in nonjury civil cases in the district courts of Texas shall be followed. When necessary to ascertain facts not reasonably susceptible of proof under those rules, evidence not admissible thereunder may be admitted, except where precluded by statute, if it is of a type commonly relied upon by a reasonably prudent person in the conduct of the person's affairs. The administrative law judge shall give effect to the rules of privilege recognized by law. (b) When testimony is excluded by ruling of the administrative law judge, the party offering such evidence shall be permitted to make an offer of proof by dictating or submitting in writing the substance of the proposed testimony prior to the conclusion of the hearing. Such offer of proof shall be sufficient to preserve the point for review. The administrative law judge may ask questions of the witness as he or she deems necessary to satisfy himself or herself that the witness would testify as presented in the offer of proof.