A few things to note as to why I don't think the hurricane upgrade was mistaken. The pressure dropped significantly yesterday, from 1012 to 998 in about 12 hours, the wind was likely catching up to this, in addition to the fact that because of the small size and higher than normal pressure around it, this caused a sharp pressure gradient, and small storms like this can spin up very quickly (and spin down just as quickly.)
Bonnie in 2004 in the Gulf, also a very small system, spun up and back down fairly quickly on two separate occasions, but didn't make it to hurricane due to higher shear and less of a pressure gradient.
The above post is not official and should not be used as such. It is the opinion of the poster and may or may not be backed by sound meteorological data. It is not endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.