Telling the others and confronting the first pair of mutineers at the night before feels like the most reasonable thing to do, but it could have bad outcomes anyway, and of course that would break the set up and it's not how dilemmas work; Instead, personally, I feel like I would go into flight/freeze/fight mode, so I would either try to separate the fighters and help to calm things down, or freeze in place while thinking about helping, just to run away for my life when the storm finally hits and things go bad. Most likely a combination of those, trying to stop the fight and maybe going into freeze mode if nothing can be done about it, and then finally flee if no one else decided to change their ways and cooperate too. It sounds rather bleak, but it's how I've seen myself react to those sorts of situations in my life, so it's the most realistic answer I can give to this.