you make a good point, but i dont think one law can really trump the other one. besides it is still written that the event must provide storage. also have to consider the source that told you this...a cop.
im sure if you really tried you could get it stored at a security station or something but like you said, you're going to be jumping through hoops to do it. probably take at least an hour or 2 for them to finally figure out what to do. personally id just conceal and hope for the best, the fair down here doesnt exactly have the best crowd of people