I don't buy it. Too many details don't add up. It's been hashed out on other forums for a while now, with the general consensus being it was totally blown out of proportion. Several posters were at the gun show in question, and didn't notice anything unusual.
Of course, the usual black helicopter crowd was all worked up about it though.
I wouldn't trust a single word anyone with the BATFE uttered. They've been operating without regard to actual law for years, and will continue to do so as long as they get away with it. If something like this happens at a gun show you attend, yell loud and long, until they knock it off and get out of your face. Publicity about what they're really up to is the last thing they want!