Was the shot from a stand or on the ground??? If from a stand, and the arrow lodged in the opposite side shoulder, he maybe be above all the goodies, which would explain why the deer was not at the end of the blood trail. Look how high the blades REALLY are on an animal and you'd know exactly why I say this. Dark blood is either LIVER or MUSCLE, HEART blood is A LOT, and a SHORT TRAIL, don't try to over-rationalize. I know it's your DAD, but sometimes we are WRONG about where we "thought" we hit them. Trust me, I have a doe with a hole in her head because she moved that far on the shot, and i thought it looked like it was a decent shot, except maybe a bit high when i released and watched the arrow fly!!!!