Got my first deer out of a tree stand. It was right below me and put an arrow through the lung but it was not enough to kill it and I had to track it for 4 hrs to kill it with a second shot.
I guess aim closer to the spine when directly below?
Straight down shots are ill advised with an arrow.
Better off letting them walk a bit then give them a loud bleat to stop them in their tracks when positioned properly. Tracking an arrow-shot deer isn't fun, been there done that!
I spined a moose that was directly below me, intentional shot, hard to miss. Went down where it stood. Have never had any other animal directly beneath me and if it is not directly below, a spine shot becomes a less than desirable shot.