In my earlier years, I tookthe straight down shot (e.g. <10 ft from the tree) several times and (fortunately) had never lost a deer doing it. (I'd rig my waist belt so I could lean out over the stand, and had well practiced the shot). Toughest(and last) time occured~1988 when I missed the spine and heart on a forkie, and tallow plugged the exit hole. I found (stumbled upon) the buck~200yds away some two hours later. I am a believer that straight downis not a good percentage shot, and now wait for the broadside or quarteting away. Ditto the above posts on single lung hits. If the good angle doesn'thappen, there is always another day...
-fsh