Speaking as a physician, the blow to the perpetrator's right femur, just above his knee joint was sufficient to fracture the femur. Typically a crush injury or other damaging injury to a person's lower extremities causes a fatal shock. In war these injuries are quickly treated with a blood substitute until the person can be moved into a better care facility. In earlier war like WWII, many lives were salvaged that had been lost before because of shock and death. There, they were saved with the venous infusion of plasma. In later conflicts another infusion might be chosen on a battlefield such as Dextran which is the preferred blood volume expander. For a person to survive (as shown in the film) without this regimen is very unlikely. He later does start intravenous infusion, after using the chain to traumatize the victim, yet the victim lived. All are inconsistent with additional sustained life.