Film copyright infringement has the same thing but different
By the same token, the prosecutions for people selling illegal copies of films on market stalls often aren't for copyright infringement. Because the source material is from overseas, and there are slightly different versions in different countries, it has become common for them to be prosecuted for selling an unclassified version.
So a whole workstream has sprung up doing side by side comparisons of seized versions with the version classified by BBFC.