It's hardly a definitive statement of fact, which was fortunate as things turned out, although you can't really blame Marianne for thinking that way.
Marianne Faithfull's 1994 autobiography called is a perfect example of how an assumption or rumour can be made to appear as fact.
Others followed and the projectionist switched off the film — the story of a Cockney gangster, a washed-up rock star and his two lovers — long before it had ended.