It doesn't automatically have to, and of course many films don't.
It's just that suspicion does start to be raised when a middle-aged director casts himself as a guy who has an incredibly beautiful, and I think (in NY at the time) actually illegally young girlfriend, and then a woman who was his illegally young girlfriend claims it is based on their relationship.
OK, maybe she's making it all up too, that's another thing we can't know for certain.
Oh and the same director then has an affair with his partner's 19/21 yo daughter who he has been in a stepdad role to since she was a child. After taking porno pictures of her while still in a relationship with her mum.
OK, OK, he wasn't legally her stepdad, he didn't live with her. He was still that person - her mother's partner. It's still odd. It still adds to the pile of things that make him look distinctly dodgy.
None of this means he is guilty, but it is suspicious. You are allowed to think someone's behaviour is inappropriate and suspect without that meaning you are sure he did a particular thing he is accused of. However, when someone says he did that thing, his previous form affects whether or not you believe them. Believing them doesn't mean you're judge and jury. It means you believe them, which you are free to do.
Saville was never tried and convicted either. But if a woman claims he abused her as a child, do we believe her? Yes, now, generally, we do. Because looking at him and what we know about him, it seems reasonable.
It is also the case that many, many people have got away with sexual abuse because of their position of power and/or money. So it's not an outlandish possibility.