This is actually a tricky situation for me because I read manga/watch anime and some of them have made me uncomfortable because even if they are "supposedly" legal so many of the characters look 12 years old. It is the style, I suppose. But, I am also not reading any that have rape/beastiality/characters that ARE 12. I would have to see the exact nature of his porn, but I am assuming it was more clear cut than he had manga with 18 year olds who look 12.
Owning child porn is illegal and you don't fantasize about raping children and then never have that seep into your real life. Just doesn't happen.