A false accusation is different from an accusation that wasn't provable. There have been many cases of false accusations in which it was proven that the accuser was intentionally lying in order to get revenge or reap some reward. There have even been cases in which the accuser later admits to having lied, but with zero
legal consequences.
In France the state's prosecutor is the accusation, and cites the victim as a witness. That allows pursuing the trial if the victim is pressured to remove the complaint.
