The only question if this was ethical or not is determined by his first shot. Was his first shot an ethical shot. He stated he was on a member of his families property, it was during daylight, and as long he was not standing in the road, it was legal and ethical. It is no different than leaving your decoy up in front of your stand over night and coming back in the morning and there is a buck staring it down.
Every time someone shoots a big deer people go to great lengths to discredit the hunter or the deer, that is why some of is just keep it to ourselves. If he shot the deer in the leg on the first shot, the ethical thing to do is follow up on the shot and recover the deer. Not to shoot a deer that had already been shot a non lethal shot and was still alive because he was pinned under something, that is unethical.
The angles of the two arrows can be explained easily. He simply walked around to the other side of the deer trying to get a better angle to the vitals