They use the term "ethical" and I would say it is anything but. Two of the great challenges of ethically harvesting game at distance is dealing with the environmental conditions and animal behavior. The hunter must be able to understand the wind "patterns" for shooting beyond say 300 yards or so, as well as slight humidity variations due to dark vs. light foliage, water, etc over which the bullet passes. These could be measured through the path of the bullet flight, but then what would be the use? This is where DOPE comes into play for the skilled long-range marksman. Doing it at the range is one thing, in the field is another.
Then you have animal behavior. When we are talking TOF of the bullet in the range of even 1/4 second up to 1 second or more, the slight movement of the animal takes a fatal shot to a wounding shot. Study of the game animal in the specific region is imperative to understand that when a certain animal does X, I have a window of Y seconds to send it.
That is not even to mention bullet performance at range.
I have taken many head of big game with all manner of arms. Last Saturday, I harvested a Buck Pronghorn killed at a distance of 680 yards. I have close to 1000 rounds downrange from 300 to 700 yards to measure group size, cold to hot bore shift, ballistic gelatin performance, and to assess my skill at seeing the wind, humidity, etc. in the field. I have, over the last 12 years, hunted that same unit 8 times and spent 22 days watching, predicting, measuring and learning the unit and the animals in that unit. Sure, the Buck I wanted, after waiting 12 years for my tag, got shot by a group of road hunters who shot over 15 rounds at it, but I was still happy with my harvest and the skill it took to get there. BTW, my self imposed maximum range was 700 yards due to bullet performance. I can hit the kill zone out to about 1000 with my rig, but I could not get bullet performance to ensure a clean kill. When you are more than 1/4 mile away, you have to be able to prove you can kill game cleanly.
Yes, I have a ballistics program on my phone, and it helps, but it won't teach you animal behavior nor will it teach you to read the environmental conditions across the path of your bullet.
BTW, in the movie, which was fiction, Swagger was used to frame himself, not make the shot.