ScrapMetal brings up a valid point - IF it worked you would see it in Pro Racing
Sometimes (actually more often than not) you've got to think outside the box rather than believe all the hype no matter how good it sounds. Take for instance the magnet that clamps on your fuel line and gives you 10% better mpg - if it worked don't you think all the auto manufacturers would include one?
The manufacturers have set themselves up for a honkin' law suit. They "guarantee safety and security" for all bike riders? There are far too many variables to make a claim like that. ANY injury to a person wearing the device will bring the sharks out of the woodwork for sure.
FWOG. I don't know anything about the Australian torts system but it is not the usa's so I bet they have different precedents. Also all they have to do is say read the manual and poof most of the liability is gone as long as it is not defective. And even if it is defective, is it because of user treatment?
I don't know though... that is my first take at it though.