I don't know if you're technically correct, but in practice, you're certainly not. Every team bumps cutters, because ref's aren't going to blow the whistle for not a lot of contact. Even if technically illegal, if a ref isn't going to call it, it's part of the game. As Coco mentioned, aggressive defense is sometimes the art of feeling out where the refs are and responding appropriately. But I've bumped cutters and been bumped as a cutter a lot, and the level of contact has to be pretty egregious before most refs will blow the whistle.