This story has been passed down to me over the years.  It happened probably fifty years ago.  Anyway, there were two small elevators in town, both located very, very close to one another.  One day during wheat harvest the wife of a local farmer came to town with a truckload and weighed in on the scale of elevator 1.  Exiting the scale she saw the owner at the dump of elevator 2, who waved her over and she mistakenly dumped her load there.  She then weighed out at elevator 1 and returned home.  When recounting the story the owner of elevator 2 remarked "you can really make money buying wheat like that".  Who knows if they ever settled up correctly.