Dark humor is a way to deflect the pain and stress of hard jobs. Whether it is guys tree cutting on sides of roads or riggers over the ocean platforms.
In emergency rooms across the US there were trophy boards that held interesting and often large items removed from various orifices presenting in the department over time. Not identified by patient. Not in a patient area. Just there to remind staff ruefully of the irrationality of humans. No longer permitted.
To my mind this is less about dark humor and more about abject stupidity.