I've seen Hounddog, and you never actually see any rape. It's more or less implied. Dakota trips over a plank of wood, falls to the ground, and you only see her facial reaction and hear her screams, as it is implied she is raped.
That scene was totally overhyped when it was first released. I found myself, as a Dakota fan, wanting to see what all the fuss was about. After viewing, I found myself thinking, "Was that it?".
As for the whole "I Spit on Your Grave" debacle, it doesn't surprise me that it's going to be butchered by the pathetic BBFC. Same goes for "A Serbian Film". It's about time they grew some balls and stopped wrapping this country's sensible adults in cotton wool.