Cask of...

One part of the nature of mental illness is that it doesn't like to come out (usually) in public affairs. For example, with all the events reoccuring he didn't strike until they became deeper, and deeper into the cave. It also shows that it isn't also present or predictable, a lot of people have moments leading up to something big, which then shows the true mental illness. It makes assumptions that most killings are outcomes of a person with mental illnesses. It also makes the reader assume that the guy was weird because he kept getting the guy drunk. I think one of the inaccurate ways is that they are all violent, not all those with mental illnesses are violent.