Boone and Crocket and Pope and young ARE fair chase only. If it is proved they were taken behind a high fence, they can not be entered. So I see no need for the designation. If it was taken fair chase, then I have no problem with taking it on private ground (with no high fence) and whether or not you had a guide.
If you started limiting records based on public land and not hiring a guide, you might have to weed out all limited entry hunts too.
Anytime you see something scored SCI, you can count on it being taken from behind high fence. That bull can never be listed as a world record in anything but SCI and everyone knows it was fed high protein diets and locked up in the fence until it go big enough to shoot (not hunt)