That is quite funny. That rarely happens, and its good you got them. But make sure it is the actual items because i have actually traded my shako for a skullders ire and other items that turned out to be all whites when i opened inventory afterwards. I hate scammers.
i believe he was simply an idiot, all laddy do and stuff, they're ladder so prolly less likely, but it doesnt matter, and the items are real for first one
I hope you know that having duped items isn't really detectable unless you have more than one duped item on a character at the same time, so if you think something is duped just don't trade for the same type or use the same type of item in that character.