Sometimes in reading a difficult Rishon or Acharon, you come across a statement which seems limited and difficult to understand. Sometimes it's what seems to be an answer to a question which skims over the main point; other times, it seems as though they didn't logically work out the implications of their statement.
Are we allowed to excuse a statement of a Rabbi, in the face of opposing logic or even scientific proof? Are all Rabbis infallible? Issues that need to be addressed in an answer include: what type of Rabbi (Rishon, Acharon, or another category), and what type of statements (Halachic, scientific, philosophic, etc)