ORIGINAL: Wheatley
It doesn't look like 100 yards in the video to me but I could be wrong. It's hard to tell but I would say it wasn't that far. Of course there is no way to prove it.
Humans are, for the most part, horrible at judging distances with the naked eye, especially without much for size references like the video.
Either way you look at it, its an unethical shot to take but it
was one heckuva a goodshot though.