It's odd in that you buried your mitigating phrase about his punishment being significant in a not-very-prominent position, a spot where you don't really want to put either a thesis or a concession (unless, of course, you're trying to dismiss the concession, which is what I think others read). Had you either opened or closed with a firm declaration that Polanski's got something coming to him, you would have appeared less to be making an apologetic argument on his behalf.

To your credit, the mitigating phrase opened your last or next-to-last paragraph (depending on whether we count your closing thought on the five best living directors as part of the same piece). It was followed, however, by a "but" that steered you back into the tone of the earlier paragraphs, wherein you listed all of the extenuating circumstances that might, to be sure, have helped create a disordered personality capable of extreme acts.