It was discovered that one of the players was actually a pokemon who came disguised as a person. As that would have given him an unfair advantage given his intimate knowledge of pokemon, and the rules state that no pokemon is allowed to play in sanctioned tournaments, the staff had no choice but to DQ this imposter. Hopefully this sends a message to all the other pokemon who would otherwise want to become pokemon masters.
I won't say who this pokemon is, but let's just say it sounds like sneezing.
and you're right, if this imposter would have been allowed into top cut, the ramifications throughout the pokemon community would have been felt for decades.
hopefully this puts to rest any rumors about what happened at canadian nats.