My understanding is that at a certain point in the story, Matt will die unless he has the flare gun to defend himself. A guidance totem told me to give it to him, which I did, and he immediately fired the flare into the air, wasting it. Reading online indicates he doesn't always fire it.
What choice did I make earlier that caused him to fire it? Is there any other way to save him without it? Is the guidance totem a dirty liar that lies?