While the situation you described should not be a regular occurance, we as hunters are attempting to take an animal's life and the occasional poor shot will happen........that animal deserves our quickest and most humane effort possible. If you have an animal in such a situation, shoot again end it as quickly as you can.
I know as a hunter I always feel a touch of remorse for ending an animals life, but the taking of it's life now provides my family with many wondeful meals.
It's the circle of life.......whether its a burger from McDonalds, a piece of Kentucky Fried Chicken or a fillet O fish.........its the circle of life.
It's killing and it's not a pretty affair, but feel no shame in what you have acomplished and provided for yourself, but take it seriously.

I for one take this stuff VERY seriously, and have the utmost respect for the game we hunt. Think about the statement "Would you cut the deer's throat" for a second........

.......I'm not here to preach ethics and sportsmanship, but I for one will never take the time to gather my thoughts, and gear, climb down out of my stand and waste time in ending an animals life as quickly and humanely as possible.........and for what? A $10 arrow?

Always carry that sense of respect for yourself and the animals you are harvesting.