According to NDNQI a patient lowered to the floor as in this case is considered an assisted fall. There is no one person to be blamed for this patient's fall. A thorough review of the circumstances surrounding the fall has to be done. And no you should not have kept the patient in bed all day. Did he have OOB / activity orders? What is the policy on using bed alarms and chair alarms? Is there a falls prevention and management policy? Is it a good policy and was it followed?