While I agree with you that people expect factual events from their historical fiction, I do not agree that they are correct or that this is the right way to look at storytelling. Most of history would not make a good story if it was told simply "as it happened." The idea that something happened one way is another barrel of monkeys entirely, for every person has their own perception of events and the history we read in high school even has the bias of the author written all over its pages.

Granted, Chaplin and Marion may have never met before (at least not in this steamy situation) and perhaps some records can prove this as "fact," but Glen David Gold's art is not concerned solely with "fact." He must convey certain truths to a reader, and if this scene succeeds in representing the atmosphere of Chaplin's own life or his times for the reader, then Gold has done an exceptional job. The "truth" that a reader may gain from a novel can be very different from the "facts," because the themes take precedence over what "actually happened." Since we may not grasp all of the facts (do we ever?), the "truth" that Gold is trying to convey is much more important.

That is something our "reality" starved culture fails to comprehend. All of our stories, even reality television, deal with falsehoods in order to inform the audience of a truth. All artists tell lies in order to reveal the truth.