The other thing I heard this evening, but haven't been able to confirm yet is that the "hoop of fire" wasn't scheduled to happen between the 1st and 2nd quarters. But the game was getting out of hand, and they wanted to let things coold down a little bit. It was supposed to be a stall.
They would have been out there for another couple of minutes, "trying" to put out the fire with those CO2 extinguishers, before using them correctly. Unfortunately, one of the members of the Fire Department didn't know it was a stall, and broke out the chemical extinguisher. And the whole thing just got out of hand.
But if the story is correct, the schedule was changed and it was for the purpose of stalling...just not 20 minutes worth.