Clint's fondness for depicting violence against women

Exactly. The whole town was complicit in the murder of Jim Duncan. The drifter was a ghost of vengeance that drew his power from the town's guilty conscience. It's noteworthy that the drifter didn't just march into town and blow everyone away. In fact, at first he didn't pick a fight with anyone, even if he was there to eventually do exactly that. It's almost as if he baited them, drawing out their true, ugly underlying natures simply by existing among them. In the brutal and disturbing rape scene, the woman slammed into the drifter purposefully on the street with the intent of provoking a hostile confrontation. He wanted to walk away (or pretended to), but she wouldn't have any of it and proceeded to spit unprovoked insults and smack his cigar. His counter-insults I interpret as the ghost of Jim Duncan's vengeance stripping her of her thin pose of respectability and drawing out her truly ugly nature, the dark part of her that willingly facilitated the ex-Marshall's execution. It was only after she was drawn out that the drifter inflicted his punishment. In the context of this film, viewing that rape within a normal, decent person's ethical framework is completely off the mark.

If you want to criticize Eastwood for having a cavalier attitude toward rape, a stronger case would be with Mordecai's dumb remark that she came back at him with a gun because, maybe, he didn't "come back for more." I never liked that line, which I do think reeks of 70s style sexism.