The scene where Nick puts out the fire before it ignites the explosives

In real life, there is no way Nick could have put out the fire. In the movie, he is lucky enough to put out the first fire with a fire extinguisher and then stomping out the remainder. However, an ember from the original fire starts a new one on a nearby sawdust (?) pile. This threatens to spread to the explosives via a gasoline spill. He ultimately stops it by setting off a sprinkler head in the nick of time. However, this fails to take into account the fire was ON THE GASOLINE. Therefore, WATER would NOT put the fire out and would make it spread even quicker.