”Vomiting black water and complaining of stomach pain”... Sudden death after knee surgery = South Korea

A female patient in her 70s who had undergone knee replacement surgery in South Korea suddenly died. Her family members expressed frustration, claiming that the hospital had ignored their request to transfer her to another hospital.
On January 4th, Mr. A, 74, underwent knee replacement surgery and started experiencing abdominal pain and vomiting two days after the surgery. After that, Mr. A complained of even worse pain and suddenly died three days after the surgery.
On the 6th, JTBC reported that he died in a hospital in the city of Hyeong-do. In response, the family of the deceased claimed that the hospital had failed in its management responsibilities.
"Even though he was breathing, they didn't perform CPR until he stopped breathing," he said. He also claims that the hospital ignored his request to be transferred to another hospital.
In response, the hospital has stated that "the operation itself went well, but there was nothing we could do as he died suddenly and for unknown reasons."
The police explained that there was no record of the victim having requested a transfer to another hospital, and that the police investigation concluded that there was no suspicion. An autopsy conducted by the National Forensic Service determined that the cause of death was acute intestinal blockage and complications.
A medical specialist told the media that "If there was paralytic ileus, it would have been possible to check that area with an X-ray or something."
Meanwhile, the hospital has filed a lawsuit against the bereaved families, who have been protesting for four months, for defamation and obstruction of business.