Yes, I have purchased a pin at DLR and someone told me it was fake. LOL I said, "really? I have the receipt right here" because I had purchased the pin earlier that day. The pin in question was for my collection but it was an LE and I think the "professional trader" in question wanted it for HER collection. She said to me "I like that pin" and pointed to it on my lanyard, I said "oh thanks, that one isn't for trade, I'm adding it to my collection" and then she said "oh, well I'm thinking it's a scrapper, but I like it so I was going to offer to trade you for this one" and she pointed to a rack pin that I didn't like. I then said "what makes you say that?" and she pointed out something like a color difference or a divet in the paint, something small that I did notice when I bought it but it didn't bother me, I then said "really, well I have the receipt right here" and she actually said I should return it because it was obviously defective. LOL I just shook my head and did not do any trades with her.
FTR I truly believe that NO ONE is any type of expert in telling what's a scrapper or not a scrapper. I think some people know some things and others know other things but NO ONE is an expert.
As a quick example there is a pin that was a GWP in DLR last year, it's Mickey Mouse in a Matterhorn Bobsled, it's supposed to say "Bobsleds" but instead it says "Bobleds" the s was dropped. This pin passed QC and shipped to the DLR where it was given out free to many many people (we have 2), the defect was discovered, DLR stopped giving the pin out and destroyed them, this is an error pin and not a scrapper and some people consider them quite valuable. We have 1 in our set and 1 extra, no one wanted it. LOL There was an error pin I saw on eBay, it was Pongo and Lucky, Pongo's collar was red, it was supposed to be blue, it was an error pin because it was distributed by Disney. I think that's the main difference, if the pin was never distributed by Disney it's a scrapper, if it was it's an error pin.