"before a car rolls back and causes an accident"
I think we are making a bigger issue out of this than is necesary. As experienced drivers, knowing the handbrake doesn't work, we will always leave it in gear, and the technique which does work is, before applying the handbrake hold the footbrake down and then pull up the handbrake.
No it's not right, and Morgan or one of us [Simon from Mulfab?] will have to redesign the thing, in the meantime, go and put some miles on the car, I promise it gets better.