you can see on the pic the nut on the left is the original Specialized one and the one on the right is the replacement one. The original has the black plastic around the outside, so the metal part (now a bit rusty) has a very small clamping area. This would slide into the recess where the tag lines the dropout, as it is only marginally bigger than the recess.
I had a look at my Deore front QR and it has the same design as the Specialized, although it doesn't cause problems on the front. The nut I used was off a cheap skewer that I had lying around.