There are procedures against falsity. Film is an art form so powerful and arrogant as to claim exemption from such discipline. Most films are fiction, which is no problem. Any old distortion will do to sell a picture. The reputations of public figures may have their recourse.
History can doubtless look after itself.
I am against public censorship. I am even against censoring lies. But liars should not get away scot-free. Films distributed in Britain are still certified by the amount of sex and violence considered appropriate for differing age groups. Where they claim to reconstruct history or tell a true story, they should also be subject to some test of accuracy.