This phrase from the interviewee is most likely to raise concerns regarding potential control deficiencies or fraud risks, because it indicates a lack of segregation of duties and proper backup arrangements in the purchasing process2. Segregation of duties is a key internal control that prevents or detects errors or fraud by ensuring that no single person has complete control over a transaction or activity3. Proper backup arrangements are also important to ensure that the purchasing process can continue smoothly and effectively in the absence of the department manager4. If the department manager cannot take more than a few days of vacation, it may suggest that he or she is trying to conceal some irregularities or misconduct in the purchasing process, or that there is no adequate supervision or review of his or her work5.
References:
1: Internal Audit Interview Questions & Answers - Wisdom Jobs
2: Segregation of Duties: A Key Internal Control - The CPA Journal
3: Segregation of Duties - The Institute of Internal Auditors or The IIA
4: Backup Arrangements - The Institute of Internal Auditors or The IIA
5: Fraud Prevention Checklist - The Institute of Internal Auditors or The IIA