From 25 feet up and at only 8 yards and not getting a pass through i could see you not getting any blood. Im sure the blood started pooling up internally but it would take a lot to get it to come out that high up on the body. But from where you think you hit him id say he should be dead close by. Get out there in the morning and keep following the trail past where you last found him and he should be close by. Good luck