I have heard some folks with a pile of elk experience tell me that once you are close to a bull, there comes a point that they almost are stupid about ignoring something out of the ordinary. At 50 yds, they'd panic at the sight of someone standing in the open, but at 15 yds you are just part of the living room furniture!
One old timer explained it to me this way: Elk have a comfort zone and it is generally established by the cows of the herd. Anything outside of that boundary is considered a danger, but once it is inside the boundary it will be ignored because to get into the herd you must obviously be one of the herd.
I still think if I had been your son even with just a lowly spike bull at 10 yds, I would still have badly offended that bull's sense of smell.
