Actually most people don't soil themselves when they die. And there's no indication from the photos that the girl who died on the ferry soiled herself. I agree that her tights are wet/dirty because of how the body was positioned in a damp or wet environment, and her feet are dirty and wet likely because of moisture trapped within her footwear, which was probably removed right before the photos were taken. Those that soil themselves usually release their bladder (if it's full). The anal sphincter does relax in death, but unless the rectum is full of stool or there are involuntary spasms from usually sudden traumatic brain injury expelling feces, it is rare.