Frome where I was situated, it looked like the deer was right on top of the other hunter - I would say well under 100 yards, maybe under 50. My gut feeling is that the guy is not a good shot, as I think he was the same hunter who needed two shots to drop a fairly close doe a few weeks earlier in the same spot.
Your right, being that close to private property means being able to drop a deer dead in its tracks, and that means having good discipline, waiting for the right moment to shoot, good shot placement, the right bullet, etc. But who knows, maybe he just had back luck that day. Still, it bothered me to see such a really great buck get (probably) wounded by a guy who, whether it was right or wrong to keep shooting, couldn't finish the job with five or six more shots at an animal that was just standing out in front of him.
As for hunting where I can see other hunters, that is another good point, and, after this last incident, I just might vacate that place. I should tell you, however, that in this particular wide open
area, you can see hundreds and hundreds of yards, maybe as far as a couple of miles in every direction, which, in a way, might make it safer because you know where everyone is.