Save Yourself

This is connected to the butterfly effect who will keep the flare gun or not. During the tower collapse, you'll be given an option to Save Emily or Jump to Safety. You can attempt to save her once and you'll get the second and last chance to continue attempting to save her or jump to save yourself. Do not attempt to save Emily twice if Matt doesn't have the flare gun. He'll get killed by the wendigo in the mines later on. If Emily has the flare gun, and you still want Matt to survive, just jump to safety so that he won't encounter the Wendigo anymore.

Butterfly Effect Update:

In Chapter 10 whether Matt skips encountering the wendigo or using the flare gun to deter it, he'll show up alone or with Jessica (if she survives her Death flag). However, Matt still needs to go through two more deathflags (alone or with Jessica) by hiding from the Wendigo during the chapter in order for him/them to survive the game.