As a post script, I shot a big bodied 4 pointer in the bean field from 30 yards about an hour and 15 minutes later, so he didn't ruin the hunt for the day. I'm not complaining about a whole "this guy ruined my hunt..." thing. It was public land, and he had every right to be there just like I did. My concern is the safety/hunter etiquette thing regarding approaching another hunter without ID'ing yourself.
Mike