In a recent episode, he said "from whence." "Whence" means "where from" or "from where." So "from whence" is redundant.
A while back he use the expression "that begs the question" in the wrong way that everybody uses it. If that raises a question don't say it begs the question. That means "that assumes the premise in the conclusion," which is not what you mean when you raise a question.
Marshall is kind of a Cliff Claven (from "Cheers") in that he is a know-it-all who does not always know it all.
