Read the story. They didnt hunt late. They shot fairly early and didnt make a great hit. Watched the elk for a long time before dark. Have you ever encountered Griz while in elk country? Have you killed an elk in Griz country? I have done both a few years ago in Wyoming. Did not encounter a bear while skinning but did encounter a huge sow with 3 very large cubs one morning. Then a boar was chasing the same 3 a couple miles away in the evening. 7 bear encounters in one day with no dead elk. Glad you are tough guy and can handle skinning and quartering an elk into the night in that country.
I read it and went back and double checked. It says that the bull was shot just before dark. So, I'd say that is hunting late. One of my misgivings about archery hunting, is the need to let the animal die undisturbed, if the hit isn't clearly fatal. Not too big a deal if shot in the morning. It is almost guaranteed that the meat is going to spoil if you leave an animal the size of an elk, undressed, overnight.
I can't know, but the wound on the elk's flank looks too straight to be caused by a bear or birds, tearing at the animal. I think that is where he hit the elk with the arrow. That would certainly put an animal in immediate distress. It would also be a long slow painful death.
Imo, if the group had time to pose for some trophy photos, and take the head, they could have more ethically skipped the photos, and gotten the meat. The meat would have been likely inedible, but it is callous to just take the head, and leave the carcass in the field.
There is no mention in the article how far the shot was. It was by the result, a shot better not taken. It would not shock me if the shot was on the longer side.
