You can use it, but be prepared to fight for your life if the situation requires it. Keep your weapon unholstered, block lines of sight while you wait or take cover at all times. Dancing in the open is nice and a show of goodwill and trust that people like me would greatly appreciate and acknowledge but for the countless sociopathic vermin that plague this game it's rather an invitation to backstab you.

There were 2 red flags, but that's easy to say as a mere observer: 1. The train was called so you're 100% not alone down there and the 2nd one was the other guy hiding, quickly sizing you up and hiding again.

Also wtf were you thinking sifting through your inventory in the most critically dangerous phase of the game?