Great story.. i have something somewhat similar..
Myself and Andrew were shooting with our 8x10 setup at the worst part of Vancouver and we were feeling quite safe that we were watching each others backs. Then came this really old building and we set up our cameras and started shooting.. Building looked like it was abandoned.. it was right by the rail road tracks so there was an occasional train pass and all the conductors were nice enough to say hi.
We kept shooting away then door of the building opened and a guy came out.. he was by no means a scarry fella but we were scared alittle.. he looked at our cameras and watched us.. then asked me where i bought my camera from and that he never saw an 8x10 before. That sec. i realized that he wasn't just an ordinary joe from the street.. He told me that he also is a photographer and pulled out a 4x5 pinhole camera and bunch of film holders from his backpack.. I was really suprised to see that and stopped what i was doing and gave full attention to the fellow.. He showed me his custom made pinhole camera which he told me that i could purchase from beau photo here in vancouver.. then told me that that building was his workshop and studio and there are bunch of other studios in there aswell..
So i got schooled on not to judge the book by the cover too..