To get the "Not Part Of The Job Description" trophy, you must rescue Kidman from the water tank without Joseph taking any damage (he is your teammate) in Chapter 5. Joseph's health bar is displayed on the left side of the screen. If he loses any health, you must immediately reload the last autosave. It is fine if Joseph loses health before this part of the mission, but he is not allowed to lose health during the water tank part. It is recommended to attempt this in New Game+ mode since you will have significantly better equipment. Thus, if you have trouble doing this during your first playthrough, try it again during your second playthrough. The start of the fight is by far the hardest part. There are lots of enemies coming from all directions, and Joseph is standing in the middle of the area without any cover. The best strategy is to use grenades and shoot explosive bolts and shock bolts on the ground in front of the cages where the enemies come from. The bolts act like mines and explode when an enemy gets close to them. The explosive bolt is very useful, as it will often take out three or more enemies at once when they come running out of the cages. The shock bolt stuns enemies for a moment, which gives you time to clear the area. After the first big wave of enemies are dead, it gets increasingly easier. The number of enemies in each wave will drop, and they will come from one direction only. Kill them close to their spawn point so they do not even have a chance to get close to Joseph.