This should be a good lesson learned. Too bad you lost the deer. But at least two things you said gives me pause. One. you weren't too sure about your shot placement and two, you found your arrow with only partial penetration.
My advice to you would have been to let the deer go for at least 4 hours or better yet, til the next morning. This happened to me a few years ago with a buck. I started trailing it after what I thought was a good hit only to jump it about 150 later. I left him and came back the next morning and found him 75 yards away.