I tried to manage the event, as I manage any and all GBA/DS tournaments at the big TCG events in the area, so I had a little bit of leverage, but it didn't help out much. There was a kid with an Infernape that kepty 1-hit-ko-ing any and everything with Overheat, despite the move constantly lowering it's special attack stats, it was able to kill anything. It even plowed through my shuckle in one hit.
I brought it up to the guy in charge, he basically shrugged. I asked the kid if i could see his infernape's stats, he refused. The guy in charge then asked, and the kid refused again, and left. The kid had just beaten my girlfriend, so a bunch of us basically asked the guy in charge if she gets the victory since the kid was disqualified. He denied us. "She lost, she's out of the tournament, even if she lost to a cheater."
This went on all day. Another kid had a team of all shinies, all with good natures, egg moves, etc. The store manager wouldn't allow us to question him much further cuz "he's just a little kid."
Futher on, a kid showed up with a shaymin on his team, we pointed it out, and the manager basically said "As long as the kid doesn't use it, he's ok." Despite what the official rules Nintendo sent him said.