I'm not sure I'd agree. The trace is quite clear in that video. I've seen lots of animals shot in the scapula/spine drop their rear end first. Neurologically, this is a reasonable reaction if the CNS is disrupted behind the front shoulders.
The wind was fairly calm and constant, judging by the slow drift of the elk's breath. I would guess about 2-3 mph FV at the elk's location, which would only drift the bullet about 7" or less if they are above 3000 feet ASL. Of course it's nearly impossible for me to accurately judge the wind from shooter to target based on the video alone, but the sort of wind seen in the video is usually fairly easy to judge and shoot in.
