I have two issues with the scenario.

1. Can the shooter successfully make that shot at least 90% of the time in practice, under similar conditions? If the answer is no (and I'd wager a lot that it is in this case), I consider the shot to be unethical.

2. Was this about hunting elk or making a long shot? I see it as the latter, which is poor ethics in my opinion. Slap steel at extreme distances if that's what you're after. Game animals deserve our best efforts, as hunters, to get in positions that allow for clean harvests. Pretty hard to argue that happened here.