idk what's in the database, whether it's rape or nudes or both. Although depictions of sexual acts versus simple nudity seems like a logical place to draw a line, all the lines on adult pornography are arbitrarily drawn based on "community standards", and we're only a few decades away from state-level bans on any nudes as "porn" in the US, including artistic photos. (Not to mention anti-sodomy laws).
Even if what's in the database is 100% violently criminal as you suggest, and even if it remains limited to that material, we already have a process in place that denies the accused of even seeing the evidence against them if a hash matches. What a horrific, orwellian situation if someone sent you hash matches, the police raid your house and now you can't even see what they think they have or prove your own innocence.
You would presumably have the 30+ images on your device or in iCloud to prove your innocence.
For you to get caught up in this dragnet, 30+ plus images have to match NeuralHash’s of known illegal images, thumbnails of those images have to also produce a hit when run through a private hash function that Apple only has, and two levels of reviewers have to confirm the match as well.
China will demand it to include pictures of the Tiananmen massacre.