Ahh, I see. Frustrating though, because such a rule contributes to the 'wrong' decision being made in a different court case. I assume that I could possibly still bring the subject up in cross examination though, even if I couldn't submit the affidavit itself as evidence? And when I was questioned by my barrister, say that I saw with my own two eyes the affidavit in which she said it. Or do you think that would also be prohibited?
Anyway, it does sound like her admission in the affidavit would still be useful evidence for me in the court it was submitted to (the Family Court, where the most important aspects will be nutted out over time), and might help to minimise the impact of any unfavourable outcome in the Magistrates Court, should I be unable to persuade the magistrate of my innocence. In other words, a family court judge may think: "Yes, you were found to have committed violence in your intervention order case, but by her own admission, so did your ex, so I won't draw any substantial conclusion from this result at this stage". Anyway, again, this is all speculation and perhaps more speculative than can really be useful at this stage, but it's still good to think about how certain things are likely to play out.
Sounds like you need to get into politics and change the system to suit you.