An older version of the list might be missing a recently compromised certificate, though. Of course, you need to both MITM someone and compromise an important cert, so that's not the sort of thing just anybody could pull off.
True, but it might be slightly less visible because you'd get an "update" instead of a failure. Also, I wonder if anyone has actually tested that scenario?
I'd like to believe that's true and that should be true, but I'd also have to actually test it before trusting it to be true.