He or she simply won't give you the attack, instead calling your actions preparation. Maybe, it's a stop hit which the referee calls a counterattack. Maybe, it' s a beat misread as a parry. Whatever, the referee awards priority to your opponent. While all referees aim for personal consistency, there is still a world of difference between what constitutes an attack.
Some referees pay particular attention to point in line, others almost never even see the line.
Some enforce strip rules religiously, others never even bring penalty cards to the strip. Remember, referees take pride in their skills. Most have spent years learning the subtlties of strip rules, and they practice directing almost as much as fencers practice fencing. The differences you notice between directors are usually just a reflection of their personality. In any case, once you are on the strip, you adjust to the way the referee calls the touch or you lose.