Basically what "dismissing without prejudice" means is that the DA didn't have sufficient evidence, but must have shown the judge he could obtain that evidence, so the judge is "temporarily" so to speak, dismissing the case until such a time as the DA has the evidence needed to prosecute.
I looked up "savings clause" and I found several meanings, however most pertained to patent law and financial law... so that one I cannot help you with. Maybe someone much more versed can help explain that in a criminal law proceeding.
But don't worry because the person who did that to you can be re-arrested and charged if the DA can build his/her case. Good luck!