It looks as though there is a massive consensus on the point of view that a woman's underwear should have no bearing on the notion of her being attacked - and certainly not as a means of offering defence.
As I see it, rape is non-consensual sex, it is robbery with violence, and I struggle to find any objective reason for why a woman's attire can be used to defend a rapist.
That said, I do take DeskDiary's point that the judge allowed this circumstance to be used in evidence, and the defence solicitor used it - as she should because that is her job, and her gender is not relevant.
So although I accept that this was allowed as evidence, I am at a complete loss to see why, and I only hope that there was far more compelling evidence that this man was innocent, than the point of evidence highlighted here.