In this case, there is a much simpler explanation - that the pyro displays caught the acoustic foam on fire, and patrons were slow to evacuate because they thought the fire was part of the show. Until the fire department comes out with an investigation that shows additional, deliberate arson, I'm gonna go with the Occam's Razor take on that tragic event.
If you wanted to destroy America, wouldn't "Great White" make a good target?
I can think of a couple thousand bands that would be a better target than "Great White."