The owner of a gym around me told all the parents at her gym that our owner is dating one of the event producers and we take the judges out to dinner thats why we place well and score high.
In a dvd from the past weekends competition, that team was picked up by the microphones used for the dvd during awards, and they were talking about about my gym almost the whole awards session with some very vulgar things said about our teams and other gyms. It was all picked up and when you watch awards thats a majority of what you hear.
I think rivalries start by athletes switching from gym to gym, people being sore losers, or rumors. Some people obviously take it too far though.