To "spook "a deer they have to detect you with at least two senses .Smelling ,hearing ,sight ,two out of three . Only one they try very hard to get another one to pick up .After a period of time if they don't detect with another scent they just go about their business if you aren't there .
Old bucks are smart one reason they became old bucks .During the rut which just happens to coincide with most states deer hunting times they run with a harem of does .The matriarch doe usually the oldest leads the way and usually the buck is right in the middle of the flock .The ladies kind of protect the "king " so to speak .