This trophy will unlock if any of the characters (Ethan, Jayden or Madison) save Shaun.
The easiest way to earn this is to make it to the warehouse with at least 2 people, this way Ethan (or whoever is rescuing Shaun) won't have to deal with Scott. What you need to do varies depending on who makes it to the warehouse.
If a character goes alone
Ethan must use a metal pole to pry open the well, and will then have the option to kill Scott. Madison will be confronted by Scott and must hit him with the pole first if she arrives alone. Jayden will shoot the lock off and must survive the ensuing fight with Scott if he arrives alone.
Two characters arrive
One character will attempt to rescue Shaun while the other must confront Scott at the docks. The big difference here is if Jayden and Madison arrive instead of Ethan and another. If Madison is killed in the fight with Scott, Jayden will fight him, and if Jayden also dies Shaun will drown.
All three characters arrive
Scott will confront Ethan and will pull a pistol out but be knocked down by Jayden, who chases him. Shaun must use the metal pole to pry open the lock and then perform CPR on Shaun. Madison attempts to distract the police, and the player must complete a series of QTE's.