Was he a big drinker? I never really knew much about the musicians in Slayer. All I cared about was their excellent stage presence. Presumably, he did have a lot of medicine given to him to handle the necrosis and perhaps some of that may have damaged his liver. Lots of medicine can do that but generally dieing immediately is worse than dying later so they still use that medicine. But could be totally unreleased. Kerry King has seemed like an asshole in a lot of recent interviews when asked about Jeff. It could be that he and the rest of the band knew how sick Jeff was. He still seemed like an ass.