I find this to be fairly amusing. There was similar incident when I went on a structural geology field trip- we were analyzing an outcrop, when this old man pulls up behind us in a car. He engages the teacher for about 20 minutes, then leaves in a huff. It seems as though he had found a rock in a stream that he was just certain was a fossilized foot (of one of the people who didn't survive the flood). My professor had to break it to the poor guy that it was just a smoothed, rounded chunk of sandstone, and he didn't like hearing that after he'd been saving on to it for 30+ years.
Now I'm in meteorite science, and righteous indignation is extremely common amongst people who "know" they have a meteorite, only to be told by us "so-called experts" that it's just a piece of magnetite.