This aspect of the hobby happens all the time, especially in Japan. Fish are kept at the breeder's or dealer's facility, and then brought to the show on behalf of the owner. The only difference here is that the fish is OWNED by the hobbyist. They also pay for the service, so no collusion there (usually). These fish don't usually touch the hobbyist's pond, ever.
What Antonio is stating is just plain "game playing" with the rules of the show. I don't know about blaming the hobbyist, it's a good deal for them, but the dealer and his fish should be banned from shows as this goes against the grain of the "hobby" and the amateur show, as these fish are not "owned" by amateurs until after the event or judging is over. This is exactly the type of thing that gets JR's hackles up. Surprised we haven't heard from him yet on this issue?
Mike