I don’t get it. If they don’t put the fire out then plants and animals will certainly die. Possibly humans too.
I haven’t read the case, but my guess is that the judge (and the law he’s relying on) focus on persistent “threats” to the environment. Of course an uncontrolled fire will kill plenty of plants and animals, but it is a temporary event and, in a way, a natural process to which living things have had time to adapt. If, to fight that temporary destructive process, you put something into the environment that is not “natural” to that local area, then you might be causing more long term harm than short term good. All that said, I personally think we should go after fires with whatever we’ve got that works most effectively and economically. I don’t discount the long term harm argument in principle, but I don’t think we currently know enough to be able to predict long term consequences.