The setting of the ring dictates the smallest aperture that the camera is able to stop the lens down to in S or P modes. If the ring was at f/11 then chances are you were OK, as the ring only prevented stop down if the calculated aperture was smaller than f/11. If the lens was wide open then it wouldn't have stopped down at all.
I don't know how this mechanism interacts with flash though. Even if the lens couldn't stop down to the correct aperture, TTL metering might have saved you, on the other hand maybe not.
Ian