Something trivial, even if inaccurate, is not libelous. A plaintiff can allege libel, even if you call your script fiction. Libel can be express or implied. It covers anything published, from a movie to an Internet posting. If you describe an important feature of a person, accuracy is crucial.
Truth is an absolute defense to a libel charge.
No matter how damaging a portrayal may be, if it is truthful you win. When you write about a famous person, you have additional protection. A well-known plaintiff must prove that the material is libelous and that you knew it or recklessly disregarded information about him or her. This defense applies whether you are writing about a government official or a movie star. You can make an honest mistake about celebrated people.