I don't think the identification of objects is at issue: it's obviously
more what the object's owners do with that info that makes some hesitate
to provide information.  Several years ago, I worked at a small
archaeological museum in Connecticut, and someone brought in a South
American basket quiver thinking that it was some incredible 17th-century
New England antiquity.  I told them what it was and sent them on their
way.  Several months later, I was cruising a local antique/junk show and
saw the same quiver.  Since I was looking at it, the owner/proprietor
assumed I was interested, and stated that it was a 17th-century New
England basketry quiver, and that Ann McMullen, curator of the museum I
worked at, had authenticated it!
 
Ann McMullen
Curator of North American Ethnology
Milwaukee Public Museum
 
P.S. At the same job, I once broke the land-speed record getting to
someone's house to see what was reported to be a dinosaur tooth. It was a
crenelated boulder the size of a VW Beetle sitting on the back of a flatbed
truck!