The burden of proof thing is difficult
Until a few decades ago some women were unable to withhold consent in law (wives, maybe prostitutes?)
Then they said that these women could be raped, but the defence people still used peoples preconceptions to put women in the category of "not rapeable" by basically trying to show that they were promiscuous or immora in some other way
Then the law was changed so that defence lawyers were not able to scrutinise the victims past as a matter of course. As I understand it though, they can still apply to the judge to include this and there was an article someone linked to with some lawyers and they said that they always applied to be able to do this as a matter of course
There are also directions that are supposed to be given by the judge to the jury to try and dispel rape myths eg a woman agreeing to have a drink with a man does not automatically mean she consents to sex
However
Time and time again, juries judge that women were consenting in the most bizarre of circumstances, their private lives are still picked apart etc. It still stands that if the defence people can show the jury one or more of the myths about women "asking for it" then they will find not guilty.
There is also this huge issue of rape being prosecuted badly, the police not gathering evidence/not taking complaints seriously and so on.
I don't think the burden of proof needs to change, I think teh police and CPS need to buck their ideas up and much work needs to be done to break down rape myths in the minds of the public and juries.
I think that's what i think anyway, teh burden of proof thing is something that I have only just started thinking about on this thread.