I'm so sorry for the loss of your sister.
My second husband eventually recovered from his episode, but it was almost exactly what you describe. He went into the hospital for pneumonia, went into withdrawal, and began hallucinating and becoming violent to the point he was in restraints. Then he went comatose as his liver and kidneys failed, was yellow to the point he looked like he had been dipped in yellow food coloring, blew up with ascites. Horrible and, yes, terrifying to watch. The doctors said IF he recovered he would certainly need a liver transplant. He barely pulled through, and was still suffering from jaundice, ascites, and encephalopathy (mental confusion due to ammonia in the blood from liver failure). When he recovered enough for a biopsy, it turned out he had EARLY cirrhosis, and would be fine if he never drank again. Sadly, a few months later, he went back to drinking and is still drinking himself to death, so far as I know. That was fifteen years ago and I don't know how he is still alive.