If you look at the page source code it was last updated in 2005. I'm guessing it's just stale rather than maliciously misleading.
I agree, I doubt that they're deliberately trying to mislead. The registration thing sounds confusing though, and I could see how someone could take it to mean registration is required.
Beyond that, should it even be legal for the sheriff to keep a gun registry, even it it's voluntary? I don't think so, personally.