That deer is standing perfectly broadside, and you can see both entrance and exit..I dont see how it could be possible for this arrow to have reached spine....much less below it. I too think a backstrap wound and a flesh wound out the other side. The entrance is dang near right on top of the buck...this doesn't bode well for a 15-20 yard shot....If I was a betting type guy, I say he lives...but only time will tell.