The most important concern when assigning multiple risk owners for an identified risk is that accountability may not be clearly defined. Accountability is the obligation of an individual or group to take responsibility for the risk and its associated actions and outcomes. If multiple risk owners are assigned for the same risk, there may be confusion, conflict, or overlap in their roles and responsibilities, and they may not be held accountable for the risk management performance. Risk ratings being inconsistently applied, different risk taxonomies being used, and mitigation efforts being duplicated are other possible concerns, but they are not as important as accountability not being clearly defined. References = ISACA Certified in Risk and Information Systems Control (CRISC) Certification Exam Question and Answers, question 12; CRISC Review Manual, 6th Edition, page 215.