In the Lyons case, the current provisions were challenged, but they held up because the crown prosecutor had discretion to go ahead or not, and the judge had discretion, amongst other things. I'm trying to remember—it's been a while since I read the entire decision—but there was judicial discretion, the burden of proof was fair in the circumstances. The burden of proof did not lie with the accused, and the prosecution had to prove beyond a reasonable doubt—
On November 14th, 2007. See this statement in context.