BillnTeds, Lurcio
I like the idea that the defendant must speak if belief in consent is his defence
I think you're chasing a solution to a problem that doesn't exist.
IME rape defendants always take to the witness box to speak - it's usually the only defence they can make. If you don't believe me go and watch a rape trial yourself (otoh - no, don't - they're not very nice).
I've done jury service 3 times, and in each of my stints one of the trials was a rape - I don't know whether I've just been 'lucky'
or whether it just reflects that a lot of jury trials are for rape. Most recent one was a couple of years ago, and I remember the details of that very well.
In all three cases the defendants chose to speak. In all 3 cases (ISTR) they were the only defence witness. In at least one case the defendant effectively convicted himself on the stand - one person making up a story is no match for 12 people critically comparing that story against all the other evidence they've heard.
So 3 cases, 3 convictions. We spent hours debating every single scrap of evidence - but there's not a shred of doubt in my mind that we got it absolutely right.
So having seen this from the inside, I'm totally convinced that the 'trial by jury' part of the system is working fine, in particular the last trial was very good indeed (police, CPS preparation etc). I believe the conviction rate for rape cases that go to trial by jury is now around 60% - which is exactly where it should be. It seems to me that it's getting to that point which is the challenge.
Bear in mind that forensic science has pretty much put paid to nearly all defences to rape ("it wasn't me" etc) - the only one left is 'consent' - which of course is why we're discussing it.
At my last trial the prosecution opened with an outline of the case and then a very long and detailed discussion about the exact wording and meaning of the current law, the concept of consent and what it did and didn't mean. The defence opening was shorter but did pretty much the same. So after the first hour or so, before we had heard a single witness, we were all very clear on what this case was about, and what we had to do.