I just bought a mint set run on eBay and the 1996 set came with 2 "W" dimes - has anyone ever heard of that happening before?
These things hide in the packaging. Many have probably been tossed in the garbage lost in the papers. I'd guess a seller didn't see there was one in it so put in another. It's not impossible for the mint to include two but they'd be right together if so.
Or someone in the past that had multiple sets looked at them and accidentally put two of them back into one set. Since the W coin is in its own little pliofilm pack it is easy to do.
