The CO's I know of would be willing to look the other way on this one. If they hear one shot after shooting hours and upon investigation it is clear to them that it was a shot made to finish the deer off, they would not make an issue of it.

Last spring during Turkey season, I happened upon a 1 year old baby bull moose that was infested with ticks and had no chance for survival. I went to a nearby farm and called the CO. He asked my to expire the animal and he'd come later on to pick it up.