Had this happen at Ft. McAllister in GA. Sites are first come first serve. I was outside loading the truck bed and guy in fiver saw our tag and asked when the site would be available. I said the earliest would be after I had finished breaking down and eating my breakfast, and the latest would be checkout time. I had a great site so I can see why he was chomping at the bit to get in it ASAP. He didn't make a fuss, so I asked him if he wanted me to put his tag on the site. He was surprised and said sure! As I was pulling out, I saw him in the staging area and told him through rolled down window that it was all his.
Anyone who has the slightest amount of experience camping in a reserved site knows about check in and check out times. No reason to be trying to bend others to your schedule by hanging around and getting underfoot.