I can't comment on the legal accuracy of that interpretation of the law, but as someone who has performed jury duty on a number of occasions I can say that whatever the letter of the law, character assassination, in lieu of objective evidence, is common and very routine.
Your jury duty experience was different than mine then. I sat on a criminal trial where we were told almost nothing about the numerous past convictions of the defendant, the fact that he beat his girlfriend, or the fact that the trial's key witness had been beaten shortly before the trial began in an apparent effort to prevent her testimony. I learned about all these things only when the trial was over. The judge even threw out a recorded phone call that the defendant placed from prison because it repeated some boilerplate disclaimers about the call being from a prison inmate.
My jury experience led me to believe that evidence rules are very stringently applied.
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).
