A drilling crew in was in the process of running 4 1/2″ tubing. A joint of tubing was being made up in the rotary, while another joint was being hoisted in from the V-Door. As the joint of tubing from the V-Door was being moved toward the mouse hole, the rig floor crewman missed the mouse hole opening as the air hoist was being lowered. The joint of tubing on the air hoist laid over toward and under the descending top drive. The top drive set down on the tubing causing the tubing joint to shoot across the rig floor. There was damage to the tubing joint; however, no injury to personnel occurred.