It seems to me you are comparing apples to oranges: Criminal charges are not the same as a civil suit (i.e. "being sued"). It is why I opted to not put in my two cents: I think my experience probably doesn't apply.
They're not the same, but it appears that evidence rules apply to both. In particular, the Federal Rules of Evidence that I cited applies to both, according to Wikipedia: http://en.wikipedia.org/wiki/Federal_Rules_of_Evidence
My experience with this: I worked at an insurance company for five years. A lot of what we did was driven by questions of what would hold up in a court of law if we got sued. Generally speaking, proving someone was an alcoholic had no bearing on the decision (there were exceptions: some policies had odd language driving those exceptions).
