Was Amazing Grace Phantom's corps song that year?? I don't know anything about this incident, I've only ever heard of it on this thread...but maybe they did it as a sign of respect? I could see maybe the 'throwing down' mentality applied toward any of their show music from that year...but maybe they played their corps song as a tribute to the corps they were in such close competition with. Of course, this would all hinge on the members' attitude and mindframe at the time...
Just trying to put a different spin on it, again, I wasn't there, so I can only hypothesis!