That field school kid who kept pulling Roman nails out of a trench wall
I was volunteering at a dig in Gloucestershire two summers ago, and this college kid was assigned to clean up a section of trench wall before photos. He kept finding these iron nails sticking out and yanking them out with his bare hands. The site director caught him after the third one and just stood there quiet for a second, then said "those were holding the wall together for 1,800 years, mate." We spent the next hour re-setting all the disturbed layers. Has anyone else dealt with newcomers on site who get too enthusiastic with artifacts?