It must be said that there is considerable confusion about the ‘mistake of fact’ defence in Queensland, even among those who oppose its abolition.
The defence is contained in section 24 of the Criminal Code. It applies to all criminal offences, not just rape.
The rule goes that if you honestly and reasonably believe something, which is in fact wrong, then the law will treat you the same as if the belief was true.
What does this mean? Let's say you unwittingly buy a stolen fridge online from Gumtree. The seller tells you that they owned the fridge for five years and need to buy a bigger one. You have no reason to be suspicious, and so it would be clearly unfair to convict you of the offence of receiving stolen property.
Crucially, your belief about the fridge must be both honest and reasonably held. If the fridge was marked with the words “Property of the Queensland Government” your belief about the bona fides of the transaction, even if genuine, is plainly unreasonable.
A fundamental feature of our criminal justice system is the right of an accused person to a fair trial. Central to that right is the ability to plead one’s case in answer to a charge. If a person is accused of a serious offence, and they believe that, at the time of the offence, they held an honest and reasonable (thought mistaken) belief as to the state of things, then they have a right to say so. Herein likes a crucial distinction that appears to have eluded abolition proponents: just because someone argues a case in one way does not mean the jury will buy it.
This is not to diminish the work of advocates who are genuinely motivated to seek a better system of justice for all. Rather, removal of the defence will increase the likelihood of serious miscarriages of justice, with society-wide ramifications.