In all cases not heard by a person authorized to make final decisions on behalf of the department, the file, summary of the findings, and recommendation shall be forwarded to the administrator of the hearings and interviews section or, in his absence, the assistant director for driver services, for review. If there was a substantial issue of fact resolved at the hearing this shall be noted in the summary and the tape transcription of the proceeding shall be forwarded for review. The administrator of the hearings and interviews section, or in his absence, the assistant director for driver services, shall review the file, summary of findings, recommendation, and if necessary, the tape transcription of the evidence. The reviewer may either accept the recommendation by marking the word "approved" on the findings and recommendations together with his signature, or he may reject the recommendation in which case he shall append the action he deems appropriate to the summary and recommendation. In all cases the action of the reviewer shall be final.