George Lucas explains why he had his name taken off a sultry erotic thriller with a 96% Rotten Tomatoes score, directed by an Empire Strikes Back writer. Lucas was in a position to make others’ careers after the blockbuster success of Star Wars, so he was happy to aid frequent collaborator Lawrence Kasdan by helping set up Kasdans directorial debut, the 1981 thriller Body Heat. Lucas kept his involvement in the film strictly hush-hush, however, not taking an on-screen producer credit.
https://screenrant.com/body-heat-movie-george-lucas-removing-name-explained/