Im willing to bet that state law is pretty hard to circumvent, especially by the larger BMC guys. That sounds like what a bartender tells his customers so they dont think they are paying full price for a 3.2% beer. Also, if I was a beer distributor in a state with a 3.2 law, I would spread that myth like wildfire. But thats just my .02%...hehe.
I did talk to the brewmaster at a Knoxville brew pub once and he told me he purposefully reports one of his beers under its actual ABV to avoid a taxation, so it must be easier for smaller breweries to lie "on label" than the larger ones, because the fact that BMC has to distribute while the brew pub sells only on-site.
-Jefe-