Sorry to hear of your loss but you owned up to it & I'm sure learned from it.
I've stated several times over the years that I've never lost an animal but I've hunted for a very long time & shot a lot of game...& I did lose one back in the early 70's. I had just forgot.
Three of us were on snowmobiles in late November in very deep snow when I spotted what was probably the biggest, or close to biggest buck I'd ever seen. He was with 4-5 doe's.
I bailed off the machine & laid over the hood of my snowmobile & dropped him at a good 200 yds with my 6mm rifle. My buddies turned around & came back & we sit there talking for a couple of minutes & then some guys came through to our right on horseback & we talked with them for a few minutes & then went up to where the buck should have been & he was gone! We tracked him for 1/4 mile & then the tracks got into a lot of other deer tracks & we never found any more blood.
Then I realized what I had done. The week before I had been out on the big desert shooting Jackrabbits & I had changed the zero so it was dead on at 100 yds.... I had hit him low, down around the brisket probably, knocking him down & then taking my eye off him for a few minutes. Actually he had fell out of sight where none of us could see him. Bad mistake! So it does happen if you hunt long enough.

Dick