As an example, if you made a decision based on the assumption that no host would include untargetable-unlynchable-triple-killing-detective-corrupt-mayor-roleblocker, and it turned out that that role was put in there.
Or if a person has information, and you make your decision based on it, and it turns out that they received the information by talking to somebody outside of the game when their role did not allow for it.
I don't care about the specific situation that was in question, I want to know in general terms whether mafia should be considered completely results based, as unlike poker, there is no (or minimal) chance involved, and instead a lot of human emotion, and as such a "perfect" player would be able to get perfect reads and convince the town perfectly, and thus any time a player doesn't win it is due to the inherent imperfection of players.
--
http://img.imgcake.com/drakeryn/alecjpguz.jpg