Hail can severely damage the large succulent leaves of a tobacco plant.  However, tobacco has a substantial ability to compensate for leaf loss.  As long as the tobacco has time for this compensation to occur, yields may not be drastically reduced.  The closer to harvest that hail occurs, the more yield will be reduced.  Bacterial soft root can be a problem, but is not as bad as in tobacco that has blown over.  Quality will be affected to some extent due to the tattered leaves.