If I were you I would go back there in the morning and look for the arrow in the daylight. Then check the area for blood or any sign of a hit. You might have missed something in the dark if it was around 7:00PM. You just may have hit him anyway. Most peoples max range in a hunting situation is less than it would be at the range or in the back yard. Just because of nerves or less than perfect body position while in a stand. Something to keep in mind on long shots.