The pistol that inverts your movement and camera seems very buggy in co-op it effects other players when youre holding it, and in the Silent Cartographer it inverts your camera even if you aren't holding it, it makes the mission nigh unplayable.

Update: It actually changed the camera settings and youre able to swap it back to not inverted, still a bug though so it may be worth looking into. and im not sure if this is a co-op only bug cause ive only been playing this mod in co-op