Now I'm debating on skipping Dick's all together and bringing my business elsewhere (possibly NH) now that I know it was just a clarification problem.
FWIW unless it was just a fluke due to some system being down, this problem might "follow" you, as the NICS system is pretty much the same everywhere for most intents and purposes. You won't really know if that's the case until you attempt to buy something again. If you get delayed again, I'd look into getting a UPIN from the feds.
-Mike