Maybe I'm misunderstanding you, but it sounds like you're asking what I would try to get away with, and using that as a basis for how laws should be written...
No, what I was saying was is that neither the person who hired it nor his wife his wife were driving it. They could've loaned it to their son, which means that he would've been driving without any insurance and the hirer would've known that. As such, not only would they have been grassing their son up, but also the hirer would've been subject to a charge of allowing a vehicle to be used without insurance. It's a smaller penalty financially to cough up to a S192 offence when getting your insurance renewal than it is admitting to any kind of insurance dodgyness.
We all know how rare it is for parents to dob their kids in with the law. Should we make every parent responsible for what their kids do? Certainly there's an argument for yes, and I've made a hell of a leap there which isn't really fair, but I'd wager that most people would think no.
This is such a rare incident, and unfortunately it does highlight an apparent injustice in the law, but it's the lesser of two evils.