That's not true, the justification outlawing CSAM being the result of a crime is not the actual legal justification for banning it and it would not at all hold

That's not true, the justification outlawing CSAM being the result of a crime is not the actual legal justification for banning it and it would not at all hold up in court. There are plenty of incredibly disturbing videos and images of some of the most gruesome crimes committed and they are lawfully accessible and obtainable on the open Internet, including some such images on Wikipedia. The documenting of a crime is not and has never been illegal.