Polygragh should be required in any contest (of significant rewards) where the results are based on non witnessed events such as a buck contest or fishing tournament. I've personally had to take a polygragh after a win on a fishing tournament. Pretty routine possibility in most trails of any size, and I wouldn't fish a trail of any size that didn't have the possibility of a polygragh as a requirement. As far as how this deer was killed, not a clue but it could be cleared up pretty quick with a polygragh. If my name was being slandered, I would do it to clear it and then take appropriate actions...