Can't the hook up be wired to the neutral position only or at least when the E-brake is engaged.
As far as legal means, that car has no business being left without the E-brake.
On a manual, it's not a I should, it's a I MUST.
So you have grounds to sue the dealer on that alone.
Good luck. Hope it all goes your way.
Anyway, OP, I think it's time to change your user name...