Every party shall have the right to present its case or defense by oral or documentary evidence, to submit rebuttal evidence, and to conduct such cross-examination as may be required for a full and true disclosure of the facts. The presiding officer shall, however, have the right and duty to limit the introduction of evidence and the examination and cross-examination of witnesses when in his or her judgment, such evidence or examination is cumulative or is productive of undue delay in the conduct of the hearing. [Rule 154.]