Quite a few years ago my aircraft received a broadside from a ramp vehicle whilst boarding pax at BHX. The damage rendered the aircraft unfit for service and we then positioned the aircraft unpressurised to Lasham for repair.
The situation may have changed since then but when I made enquiries I was informed that in the UK it was common practice for operators to have to sign a "disclaimer" indemnifying various agencies which operate on the ramp from any claim in the event of having ones aircraft impaled by same agents.
At that time there had never been a test case in the High Court since a) operators did not want to "upset" the agencies concerned and b) the cost of such action was a lot more than that incurred by the occasional bit of rash etc.
If this is still the case then I believe this policy is misguided. As soon as these agencies feel it where it hurts most (ie by having to pay for any damage) then little will be done to ensure that the individuals on the ramp have a suitable amount of training and a disposition to take due care at all times.