One of the issues with the water is that it is very contaminated. Which means, you end up very ill from drinking the water. But you stepped out of line, so why haven't the guards shot you yet? They let you drink the water, make you think they are not going to shoot you and as soon as you turn around, you get bayoneted multiple times. But you are still breathing, so the guards shoot you in the head. You immediately die. Stopping to drink the water was not your smartest choice.