He gets away with titles and content that new authors can't get away with.

No he really doesn't.

Other erotica writers can't publish books with "pounded in the butt" in the title without getting filtered

They can & do, in fact here is an example from just last month.

The reason you don't see lots of those is because unless you are trying to ride Chucks coat tales (if you'll excuse the pun) you wouldn't name a book that, because it's a lazy way of writing, both content & a title.

It's similar to how some established authors can get away with writing stories with step-siblings or dubious consent, but most people can't.

Actually it's the exact opposite. If you are an established popular writer you are MORE likely to have such material taken down, specifically because you are popular. At which point you then move across to Smashwords to publish that material.