I was willing to give Polanski the benefit of the doubt -- that he thought she was in her 20s, that it was consensual but was later turned into a rape allegation -- but thesmokinggun.com has the transcripts of both the girl and of Polanski, and if both of their transcripts are true then I have no sympathy for a man who was clearly using the old "I'm a photographer, take off your clothes, and aren't you horny now that your naked?" schtick to pressure a woman into sex. He was boorish, and by today's standards it would have been some kind of date-rape.
Maybe in the 1970s pressuring people into sex was considered fair, and maybe back then the concept of simply ASKING a person if she wanted to have sex was just too much honestly for a man to summon... maybe that was why in that era it wasn't a clear-cut case of rape, maybe that is why they initially promised him a sentence based on unlawful sexual contact with a minor rather than a rape charge.
They'll need a time machine to sentence him properly. But by today's standards, he'd at least be given probation and community service.