From the look of the arrow it was an extreme quartering away shot with little room for error. But on a buck like that I would have tried it to. It looks like he got to make a follow up shot.
My first bow kill was many years ago when I was knee high to a grasshopper and I'll never forget it. That doe came down the hill just sweet as could be and I got excited and pulled it, drilling her in the hind quarter....luckly it hit the artery and she only went 30 yards and tumbled over, Stevie Wonder could have followed that blood trail, we all make bad shots, if you haven't then you just haven't been doing it long enough yet. I've been bow hunting for nearly 20 year, it happens.
Thats a heck of a buck no matter where it was taken.
Get'em Duck!