"The famous slap, where [Virgil] Tibbs retaliates against a racist landowner, wasn't improvised, though, as has been suggested. I kept telling [[Sidney Poitier|[Sidney] Poitier]] that Tibbs was a sophisticated detective, not used to being pushed around. I showed him how to do the slap. "Don't hit him on the ear," I said. "I want you to really give him a crack on the fatty side of his cheek." I told him to practise on me. A black man had never slapped a white man back in an American film. We broke that taboo."