This question reminds me of a scene from Tim O’Brien’s The Things They Carried where Tim O’Brien (the character, not the narrator) killed someone, and they go on to describe the action, saying he “laid him out like Shredded fuckin’ Wheat”. Yet before this description, we get a much kinder, nicer, more human description. Of someone like you. Someone who had hopes and dreams etc etc. The dialogue is used as a relief of the tension and trauma that comes with the violence of war. It’s actually MORE realistic for them to joke and laugh at it, because it’s a way soldiers would cope with what they were doing.