That the Mercier Kilo TT comes stock with a Dura-Ace cog?

Here's why I ask: I recently got a Kilo TT and hearing that the cog and lockring is trash, I immediately took the rear wheel to my FLBS and had the cog/lockring swapped out for the Dura-Ace equivalents. A few days later my son was asking me what's so special about a fixed-gear bike, so I pulled out a freewheel and the stock Kilo TT cog to illustrate the difference. It was then that I noticed "Shimano" and "Dura Ace" stamped into the cog.

So... one of two things happened: the guys at the FLBS pulled off the stock cog and accidentally put it back on instead of the Dura Ace cog I bought, or my stock Kilo TT wheel came stock with a Dura Ace cog and I now have two 16t Dura Ace cogs.